Silicone hydrogels having desirable water content and oxygen permeability

ABSTRACT

The present invention relates to a process comprising the steps of reacting a reactive mixture comprising at least one silicone-containing component, at least one hydrophilic component, and at least one diluent to form an ophthalmic device having an advancing contact angle of less than about 80°; and contacting the ophthalmic device with an aqueous extraction solution at an elevated extraction temperature, wherein said at least one diluent has a boiling point at least about 10° higher than said extraction temperature.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/579,693, filed on Dec. 23, 2011 entitled SILICONE HYDROGELSCOMPRISING N-VINYL AMIDES AND HYDROXYALKYL (METH)ACRYLATES OR(METH)ACRYLAMIDES, and U.S. Provisional Patent Application No.61/579,683, filed on Dec. 23, 2011 entitled SILICONE HYDROGELS HAVING ASTRUCTURE FORMED VIA CONTROLLED REACTION KINETICS, the contents of whichare incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to silicone hydrogels displaying desirablewater content and oxygen permeability.

BACKGROUND OF THE INVENTION

Soft contact lenses made from silicone hydrogels contact lenses offerimproved oxygen permeability as compared to soft lenses made fromnon-silicone materials such as poly(2-hydroxyethyl methacrylate) (HEMA).Initial efforts to make silicone hydrogel contact lenses were hamperedby the poor wettability, high modulus, poor clarity, hydrolyticinstability or the high cost of raw materials used to make many of thesesilicone hydrogels. While various solutions have proven somewhatsuccessful for each of these deficiencies, there remains a need forsilicone hydrogels that can be made from inexpensive commerciallyavailable monomers, and which have excellent wettability (without theneed for surface modification), low modulus, good clarity, andhydrolytic stability.

Silicone hydrogels formulations containing polymeric wetting agents,such as poly(N-vinylpyrrolidone) (PVP) and acyclic polyamides have beendisclosed. However, these polymers are quite large and require the useof special compatibilizing components, which need to be custommanufactured. Examples of compatibilizing components include 2-propenoicacid,2-methyl-,2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propylester (SiGMA).

An alternative means of forming a wettable silicone hydrogel lens is toincorporate monomeric N-vinylpyrrolidone (NVP) into the monomer mix usedto make the silicone hydrogel polymer, typically in amounts of about25-55% (by weight) of the monomer mix. Such materials have beendescribed in U.S. Pat. Nos. 4,136,250; 4,153,641; 4,260,725 and6,867,245. The materials described in these references generallyincorporate polyfunctional silicone monomers or macromers, that act ascrosslinking agents, and thereby increase the modulus of the finalpolymer. U.S. Pat. No. 4,139,513 discloses that 2-propenoic acid,2-methyl-,2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propylester (SiGMA) can be used to form lenses from formulations comprisingNVP and HEMA. SiGMA is the only source of silicone disclosed. However,because of the relatively low silicone content in those monomers,desirable levels of oxygen permeability in the final polymers aredifficult to achieve. There is no disclosure which would suggest how toincorporate silicones which do not comprise compatibilizingfunctionality into the formulation.

US 2010/0048847 discloses silicone hydrogels made from a blend of amonomethacryloxyalkyl polydimethylsiloxane methacrylate with about 52%NVP, HEMA and TRIS, and using a blend of ethanol and ethyl acetate as adiluent. The polymers disclosed are (to varying degrees) hazy, but itwas disclosed in this application that the haziness could be reduced bythe addition of at least about 1.5% methacrylic acid (MAA).

Addition of anionic monomers such as MAA can, however, cause hydrolyticinstability in silicone hydrogels, as was disclosed in “The role ofionic hydrophilic monomers in silicone hydrogels for contact lensapplication”, Lai, Y., Valint, P., and Friends, G.; 213^(th) ACSNational Meeting, San Francisco, Apr. 13-17, 1997. For this reason, itremains desirable to form clear, hydrolytically stable, wettable(without surface treatment) silicone hydrogels with low moduli from acombination of a monomethacryloxyalkyl polydimethylsiloxane methacrylatesuch as mPDMS, and NVP.

SUMMARY OF THE INVENTION

The present invention relates to silicone hydrogels comprising a watercontent of at least about 50% and an oxygen permeability of at leastabout 80 barrers wherein said silicone hydrogel is formed from areaction mixture comprising about 37 to about 75 wt % of at least oneslow-reacting hydrophilic monomer having a slow-reacting hydrophilicmonomer kinetic half life;

at least one silicone-containing component having a silicone-containingcomponent kinetic half life, which may be optionally substituted with atleast one hydroxyl containing group;

at least one hydroxyl-containing component selected from at least onehydroxyl-substituted, silicone-containing component, at least onehydroxyalkyl monomer, and mixtures thereof,

wherein ratio of said slow-reacting hydrophilic component half life tosaid silicone-containing component half life is at least 2, saidsilicone containing components comprise between 9 and 14% silicon andless than 15 wt % TRIS and all reactive components other than saidslow-reacting hydrophilic monomer and said silicone containingcomponents in the reaction mixture are present in an amount betweenabout 11 and about 92 mmol/100 g reactive components.

The silicone hydrogels of the present invention are useful for makingbiomedical devices, ophthalmic devices, and particularly contact lenses.

DESCRIPTION OF THE FIGURE

FIG. 1 is a schematic of a lens assembly.

FIG. 2 is a schematic of the cure chamber described herein.

FIG. 3 is a schematic of compartment 2 of the cure box show in FIG. 2

FIG. 4 is a graph of the Dk v. the ratio of ancillary components toreactive mixture (AC/RM) of the data from Examples 3-13.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to compositions comprising from about 40to about 60 wt % of at least one slow reacting hydrophilic monomer, atleast one at least one mono(meth)acryloxyalkyl polydialkylsiloxanemonomer; one hydroxyalkyl (meth)acrylate or (meth)acrylamide monomer,and at least one crosslinking monomer; wherein said at least onehydroxyalkyl (meth)acrylate or (meth)acrylamide monomer and said slowreacting hydrophilic monomer are present in mole percents which form amolar ratio between about 0.15 and 0.4.

It has been surprisingly found that the formulations of the presentinvention form hydrogels with a desirable balance of properties. Theformulations may be made using a range of diluents, no diluent and insome embodiments may also be cured using light.

As used herein, “diluent” refers to a diluent for the reactivecomposition. Diluents do not react to form part of the biomedicaldevices.

As used herein, “compatibilizing agent” means a compound, which iscapable of solubilizing the selected reactive components.Compatibilizing agents have a number average molecular weight of aboutless than 5000 Daltons, and in another less than about 3000 Daltons. Thecompatibilizing agent of the present invention solubilizes via hydrogenbonding, dispersive forces, combinations thereof and the like. Thus, anyfunctionality which interacts in any of these ways with the highmolecular weight hydrophilic polymer may be used as a compatibilizingagent. Compatibilizing agents in the present invention may be used in anamount so long as they do not degrade other desirable properties of theresulting ophthalmic device. The amount will depend in part on theamount of high molecular weight hydrophilic polymer used. One class ofcompatibilizing agents comprises at least one silicone and at least onehydroxyl group. Such components are referred to as “silicone containingcompatibilizing component” and have been disclosed in WO03/022321 andWO03/022322.

As used herein, a “biomedical device” is any article that is designed tobe used while either in or on mammalian tissues or fluid, and in oneembodiment in or on human tissue or fluids. Examples of these devicesinclude but are not limited to catheters, implants, stents, andophthalmic devices such as intraocular lenses, punctal plugs and contactlenses. In one embodiment the biomedical devices are ophthalmic devices,particularly contact lenses, most particularly contact lenses made fromsilicone hydrogels.

As used herein, the terms “ophthalmic product” “lens” and “ophthalmicdevice” refer to devices that reside in or on the eye. These devices canprovide optical correction, wound care, drug delivery, diagnosticfunctionality, cosmetic enhancement or effect, glare reduction, UVblocking or a combination of these properties. Non-limiting examples ofophthalmic devices include lenses, punctal plugs and the like. The termlens (or contact lens) includes but is not limited to soft contactlenses, hard contact lenses, intraocular lenses, overlay lenses, ocularinserts, and optical inserts.

As used herein “reaction mixture” refers to reactive and non-reactivecomponents (including the diluent) that are mixed together and reactedto form the silicone hydrogels of the present invention. The reactivecomponents are everything in the reaction mixture except the diluent andany additional processing aids which do not become part of the structureof the polymer.

As used herein “(meth)” refers to an optional methyl substitution. Thus,a term such as “(meth)acrylate” denotes both methacrylic and acrylicradicals.

All percentages in this specification are weight percentages unlessotherwise noted.

As used herein, the phrase “without a surface treatment” or “not surfacetreated” means that the exterior surfaces of the devices of the presentinvention are not separately treated to improve the wettability of thedevice. Treatments which may be foregone because of the presentinvention include, plasma treatments, grafting, coating and the like.However, coatings which provide properties other than improvedwettability, such as, but not limited to antimicrobial coatings and theapplication of color or other cosmetic enhancement, may be applied todevices of the present invention.

As used herein “silicone macromers” and silicone “prepolymers” meanmono- and multi-functional silicone containing compounds havingmolecular weights of greater than about 2000.

As used herein “hydroxyl-containing component” is any componentcontaining at least one hydroxyl group.

As used herein “monovalent reactive groups” are groups that can undergofree radical and/or cationic polymerization. Non-limiting examples offree radical reactive groups include (meth)acrylates, styryls, vinyls,vinyl ethers, C₁₋₆alkyl(meth)acrylates, (meth)acrylamides,C₁₋₆alkyl(meth)acrylamides, N-vinyllactams, N-vinylamides,C₂₋₁₂alkenyls, C₂₋₁₂alkenylphenyls, C₂₋₁₂alkenylnaphthyls,C₂₋₆alkenylphenylC₁₋₆alkyls, O-vinylcarbamates and O-vinylcarbonates.Non-limiting examples of cationic reactive groups include vinyl ethersor epoxide groups and mixtures thereof. Non-limiting examples of thefree radical reactive groups include (meth)acrylate, acryloxy,(meth)acrylamide, and mixtures thereof.

In the present invention the components are selected to react atspecific points in the reaction. For example, “fast reacting” componentsare selected to polymerize primarily at the beginning of the reaction,while the slow reacting hydrophilic monomer is selected to polymerizeprimarily at the end of the reaction. Fast reacting components includethe silicone-containing components, the hydroxyalkyl monomers and somecrosslinkers.

In one embodiment, slow reacting components have kinetic half liveswhich are at least about two times greater than the fastest siliconecontaining monomer. Kinetic half lives may be measured as describedherein. It should be appreciated that the kinetic half lives arerelative to specific formulations.

Examples of slow reacting groups include (meth)acrylamides, vinyls,allyls and combinations thereof and a least one hydrophilic group. Inanother embodiment the slow reacting group is selected from N-vinylamides, O-vinyl carbamates, O-vinyl carbonates, N-vinyl carbamates,O-vinyl ethers, O-2-propenyl, wherein the vinyl or allyl groups may befurther substituted with a methyl group. In yet another embodiment theslow reacting group is selected from N-vinyl amides, O-vinyl carbonates,and O-vinyl carbamates.

Examples of fast reacting groups include (meth)acrylates, styryls,methacryamides and mixtures thereof. Generally (meth)acrylates arefaster than (meth)acrylamides, and acrylamides are faster than(meth)acrylamides

Throughout the specification, wherever chemical structures are given, itshould be appreciated that alternatives disclosed for the substituentson the structure may be combined in any combination. Thus if a structurecontained substituents R₁ and R₂, each of which contained three lists ofpotential groups, 9 combinations are disclosed. The same applies forcombinations of properties.

The present invention relates silicone hydrogels which display a balanceof desirable properties, particularly a bulk water content of at leastabout 50%, at least about 55% and at least about 60%, with oxygenpermeabilities of at least about 85 barrers, about least about 90barrers, at least about 100 barrers, from about 85 to about 150 barrers,and from about 85 to 130 barrers. It is a surprising benefit of thepresent invention that both the water contents and the oxygenpermeabilities can be achieved in the same lens.

The silicone hydrogels of the present invention may be formed from acombination of three components, at least one slow-reacting hydrophilicmonomer, at least one silicone-containing monomer and at least onehydroxyalkyl monomer. Applicants have found that by controlling theamount of the components other than the slow-reacting monomer andsilicone containing components to about 11 to about 92 mmol/100 g ofreactive components, silicone hydrogels having combination of watercontent and oxygen permeability described herein may be produced. Thesilicone hydrogels of the present invention are in one embodimentparticularly well suited for contact lenses as they transmit levels ofoxygen desirable for healthy corneal function and have water contentswhich approach those of the ocular environment.

The first component of the reactive mixture is a slow reacting componentselected from N-vinylamide monomers of Formula I, vinyl pyrrolidones ofFormula II-IV, n-vinyl piperidone of Formula V:

wherein R is H or methyl, and in one embodiment R is H;

R₁, R₂, R₃, R₆, R₇, R₁₀, and R₁₁ are independently selected from H, CH₃,CH₂CH₃, CH₂CH₂CH₃, C(CH₃)₂;

R₄ and R₈ are independently selected from CH₂, CHCH₃ and —C(CH₃);

R₅ is selected from H, methyl, ethyl; and

R₉ is selected from CH═CH₂, CCH₃═CH₂, and CH═CHCH₃.

The total number of carbon atoms in R₁ and R₂ may be 4 or less, and inanother embodiment R₁ and R₂ are methyl.

The slow-reacting hydrophilic monomer may be selected from the N-vinylamide monomer of Formula I or a vinyl pyrrolidone of Formula II or IV.In yet another embodiment R₆ is methyl, R₇ is hydrogen, R₉ is CH═CH₂,R₁₀ and R₁₁ are H.

In another embodiment the slow-reacting hydrophilic monomer is selectedfrom ethylene glycol vinyl ether (EGVE), di(ethylene glycol) vinyl ether(DEGVE), N-vinyl lactams, including N-vinyl pyrrolidone (NVP),1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone; 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone; 1-ethyl-5-methylene-2-pyrrolidone,N-methyl-3-methylene-2-pyrrolidone, 5-ethyl-3-methylene-2-pyrrolidone,1-n-propyl-3-methylene-2-pyrrolidone,1-n-propyl-5-methylene-2-pyrrolidone,1-isopropyl-3-methylene-2-pyrrolidone,1-isopropyl-5-methylene-2-pyrrolidone, N-vinyl-N-methyl acetamide (VMA),N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,N-vinyl acetamide, N-vinyl isopropylamide, allyl alcohol, N-vinylcaprolactam, N-2-hydroxyethyl vinyl carbamate, N-carboxyvinyl-β-alanine(VINAL), N-carboxyvinyl-α-alanine and mixtures thereof.

In another embodiment the slow-reacting hydrophilic monomer is selectedfrom NVP, VMA and 1-methyl-5-methylene-2-pyrrolidone. In yet anotherembodiment the slow-reacting hydrophilic monomer comprises NVP.

The slow reacting hydrophilic monomer is present in amounts to providewettability to the resulting polymer. Wettability may be measured viaadvancing contact angle, and desirable contact angles are less thanabout 80°, less than about 70° and in some embodiments less than about60°. The slow reacting hydrophilic monomer may be present in amountsbetween about 30 and about 75 wt %, between about 37 and about 75 wt %,between about 30 and about 70 wt %, between about 37 and about 70 wt %,and between about 39 and about 60 wt %, all based upon all reactivecomponents.

The at least one silicone-containing monomer is monofunctional andcomprises (a) a fast reacting group and (b) a polydialkyl siloxanechain. In another embodiment the silicon-containing monomer comprises afast reacting group selected from (meth)acrylates, styryls,(meth)acrylamides and mixtures thereof. The at least onesilicone-containing monomer may also contain at least one fluorine. Inyet another embodiment the silicone-containing component is selectedfrom mono (meth)acryloxyalkyl polydialkylsiloxane and mono(meth)acrylamide alkyl polydialkylsiloxane monomer of Formula VII or thestyryl polydialkylsiloxane monomer of Formula VIII:

wherein R₁₂ is H or methyl;

X is O or NR₁₆,

Each R₁₄ is independently a phenyl or C₁ to C₄ alkyl which may besubstituted with fluorine, hydroxyl or ether, and in another embodimenteach R₁₄ is independently selected from ethyl and methyl groups, and inyet another embodiment, all R₁₄ are methyl;

R₁₅ is a C₁ to C₄ alkyl;

R₁₃ is a divalent alkyl group, which may further be functionalized witha group selected from the group consisting of ether groups, hydroxylgroups, carbamate groups and combinations thereof, and in anotherembodiment C₁-C₆ alkylene groups which may be substituted with ether,hydroxyl and combinations thereof, and in yet another embodiment C₁ orC₃-C₆ alkylene groups which may be substituted with ether, hydroxyl andcombinations thereof

a is 2 to 50, and in some embodiments 5 to 15.

R₁₆ is selected from H, C₁₋₄alkyl, which may be further substituted withone or more hydroxyl groups, and in some embodiments is H or methyl.

In yet another embodiment R₁₂ and each R₁₄ are methyl.

In yet another embodiment at least one R₁₄ is 3,3,3-trifluoropropyl.

Examples of suitable silicone-containing monomers includemonomethacryloxyalkylpolydimethylsiloxane methacrylates selected fromthe group consisting of monomethacryloxypropyl terminated mono-n-butylterminated polydimethylsiloxane, monomethacryloxypropyl terminatedmono-n-methyl terminated polydimethylsiloxane, monomethacryloxypropylterminated mono-n-butyl terminated polydiethylsiloxane,monomethacryloxypropyl terminated mono-n-methyl terminatedpolydiethylsiloxane, N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy) dimethylbutylsilane)acrylamide,α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,and mixtures thereof.

In another embodiment the silicone-containing component is selected fromthe group consisting of monomethacryloxypropyl terminated mono-n-butylterminated polydimethylsiloxane, monomethacryloxypropyl terminatedmono-n-methyl terminated polydimethylsiloxane,N-(2,3-dihydroxypropane)-N′-(propyl tetra(dimethylsiloxy)dimethylbutylsilane)acrylamide,α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,and mixtures thereof.

In another embodiment the silicone containing component is selected fromacrylamide silicones of U.S. Ser. No. 13/048,469, US20110237766, andparticularly the silicone monomers expressed in the following generalformulae (s1) through (s6).

wherein m is 4-12 and in some embodiments 4-10.

Additional silicone containing components containing one or morepolymerizable groups may also be included. Any additional disclosedsilicone components having the herein disclosed reactive groups may beincluded. Examples include silicone containing monomers displayingbranched siloxane chains such as SiMAA.

The at least one silicone-containing component is present in thereactive mixture in an amount sufficient to provide the desired oxygenpermeability. It is a benefit of the present invention that oxygenpermeabilities greater than about 70 barrer, greater than about 80barrer, in some embodiments greater than about 90 barrer, and in otherembodiments greater than about 100 barrer may be achieved. Suitableamounts will depend on the length of the siloxane chain included in thesilicone-containing monomers, with silicone-containing monomers havinglonger chains requiring less monomer. Amounts include from about 20 toabout 60 weight %, and in some embodiments from about 30 to about 55weight %.

In one embodiment the total amount of silicon in the reactive mixture(excluding diluent) is between about 9 and 14 wt % and between about 9and 13%. Limiting the amount of silicon, in combination balancing theamount of the slow-reacting hydrophilic monomer and the other reactivecomponents, provides the desirable combination of properties achieved bythe present invention. It is a benefit of the present application thatsilicone hydrogels having the combination oxygen permeabilities andwater contents may be formed with only moderate amounts (less than 14 wt%) silicon.

In one embodiment the reaction mixture comprises less than about 10 wt %TRIS, less than 5 wt % TRIS and in some embodiments is substantiallyfree of TRIS. In some embodiments, the silicone hydrogels may also bemade without silicone containing macromers or prepolymers.

The reactive mixtures of the present invention further comprise at leastone hydroxyalkyl monomer selected from hydroxyalkyl (meth)acrylate or(meth)acrylamide monomer of Formula IX or a styryl compound of Formula X

wherein R₁ is H or methyl,

X is O or NR₁₆, R₁₆ is a H, C₁ to C₄ alkyl, which may be furthersubstituted with at least one OH, in some embodiments methyl or2-hydroxyethyl; and

R₁₇ is selected from C₂-C₄ mono or dihydroxy substituted alkyl, andpoly(ethylene glycol) having 1-10 repeating units; and in someembodiments 2-hydroxyethyl, 2,3-dihydroxypropyl, 2-hydroxypropyl.

In one embodiment R₁ is H or methyl, X is oxygen and R is selected fromC₂-C₄ mono or dihydroxy substituted alkyl, and poly(ethylene glycol)having 1-10 repeating units. In another embodiment R₁ methyl, X isoxygen and R is selected from C₂-C₄ mono or dihydroxy substituted alkyl,and poly(ethylene glycol) having 2-20 repeating units, and in yetanother embodiment R₁ methyl, X is oxygen and R is selected from C₂-C₄mono or dihydroxy substituted alkyl. In one embodiment, at least onehydroxyl group is on the terminal end of the R alkyl group.

Examples of suitable hydroxyalkyl monomer include 2-hydroxyethylmethacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, 1-hydroxypropyl-2-(meth)acrylate,2-hydroxy-2-methyl-propyl (meth)acrylate, 3-hydroxy-2,2-dimethyl-propyl(meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate,2-hydroxyethyl (meth)acrylamide, polyethyleneglycol monomethacrylate,bis-(2-hydroxyethyl) (meth)acrylamide, 2,3-dihydroxypropyl(meth)acrylamide, and mixtures thereof.

In another embodiment the hydroxyalkyl monomer is selected from thegroup consisting of 2-hydroxyethyl methacrylate, glycerol methacrylate,2-hydroxypropyl methacrylate, hydroxybutyl methacrylate,3-hydroxy-2,2-dimethyl-propyl methacrylate, and mixtures thereof.

In yet another embodiment the hydroxyalkyl monomer comprises2-hydroxyethyl methacrylate, and in another embodiment comprises3-hydroxy-2,2-dimethyl-propyl methacrylate. In an alternate embodimentthe reactive hydroxyalkyl monomer comprises glycerol methacrylate.

In one embodiment, the hydroxyl containing components have the samereactive functionality as the silicone-containing monomers.

In one embodiment the hydroxyalkyl monomers are present in mole percentswhich form a molar ratio of hydroxyl groups to slow reacting hydrophilicmonomer of at least about 0.15 and in some embodiments between about0.15 and about 0.4. This is calculated by dividing the number of molesof hydroxyl groups in the hydroxyalkyl monomers (including any hydroxylgroups on the slow-reacting hydrophilic monomer and thesilicone-containing monomer) by the number of moles of the slow-reactinghydrophilic monomer per a given mass of the monomer mix. In thisembodiment, for a reaction mixture comprising HO-mPDMS, HEMA, EGVE andNVP, the hydroxyl groups on each of HO-mPDMS, HEMA and EGVE would becounted. Any hydroxyl groups present in the diluent (if used) are notincluded in the calculation. In one embodiment, the lower amount ofhydroxyalkyl monomers is selected to provide a haze value to the finallens of less than about 50% and in some embodiments less than about 30%.

Alternatively, the molar ratio of hydroxyl groups in the reactionmixture to silicon (HO:Si) is between about 0.16 and about 0.4. Themolar ratio is calculated by dividing molar concentration of hydroxylgroups in the components of the reactive mixture (other than anyhydroxyls which are part of the slow-reacting hydrophilic monomer ordiluents) by the molar concentration of silicon. In this embodiment boththe hydroxyalkyl monomers and any hydroxyl-containing siliconecomponents are included in the calculation. Thus, in calculating theHO:Si ratio of the reaction mixture comprising HO-mPDMS, HEMA, EGVE andNVP, only the hydroxyl groups on each of HO-mPDMS, HEMA would be countedin calculating the HO:Si.

In another embodiment the molar ratio of hydroxyl groups in non-siliconecontaining components (other than any hydroxyls which are part of theslow-reacting hydrophilic monomer or diluents) to silicon is betweenabout 0.13 and about 0.35, about 0.13 and about 0.3, and about 0.13 andabout 0.25. Thus, in calculating the HO_(non-Si):Si ratio of thereaction mixture comprising HO-mPDMS, HEMA, EGVE, and NVP only thehydroxyl groups on, HEMA would be counted in calculating theHO_(non-Si):Si ratio.

It will be appreciated that the minimum amount of hydroxyl componentwill vary depending upon a number of factors, including, the number ofhydroxyl groups on the hydroxyalkyl monomer, the amount, molecularweight and presence or absence of hydrophilic functionality on thesilicone containing components. For example, where HEMA is used as thehydroxyalkyl monomer and mPDMS is used in amounts about 38 wt % as thesole silicone containing monomer, at least about 8 wt % HEMA (0.16HO:Si) is included to provide the desired haze values. However, whenlesser amounts of mPDMS are used (about 20%), as little as about 2 or 3%HEMA provides silicone hydrogel contact lenses having haze values belowabout 50%.

The reactive mixture may further comprise additional hydrophilicmonomers. Any hydrophilic momomers used to prepare hydrogels may beused. For example monomers containing acrylic groups (CH₂═CROX, where Ris hydrogen or C₁₋₆alkyl an X is O or N) or vinyl groups (—C═CH₂) may beused. Examples of additional hydrophilic monomers areN,N-dimethylacrylamide, polyethyleneglycol monomethacrylate, methacrylicacid, acrylic acid, combinations thereof and the like. If the additionalhydrophilic monomers are not slow reacting monomers as defined herein,their concentrations in the formulations of the present invention may belimited to concentrations which do not provide the lens with a contactangle higher than about 80°. As used herein, “intermediate” half life isone that is between 20% and 70% faster than the slowest reactingsilicone component. For example, if the additional hydrophilic monomerhas a kinetic half life which is between the half lives of the vinylcontaining monomer and the silicone components, (such asN,N-dimethylacrylamide), the amount of the additional hydrophilicmonomer is limited to below about 3 wt %. In embodiments where the lensis to be surface modified, higher amounts of additional monomers may beincluded.

The total amount of reactive components other than silicone-containingcomponents and slow-reacting hydrophilic components (“ancillarycomponents”) is between about 11 and about 92 mmol ancillarycomponents/100 gm reactive mixture and between about 38 and about 76mmol ancillary components/100 gm reactive mixture. In another embodimentthe amount of fast or intermediate curing ancillary reactive componentsis between about 11 and about 92 mmol ancillary components/100 gmreactive mixture and between about 38 and about 76 mmol ancillarycomponents/100 g reactive mixture.

Ancillary components include non-silicone containing hydroxyalkylmonomer, additional hydrophilic monomers which are not slow reacting asdefined herein, and additional components including, crosslinkers,reactive tints, dyes and pigments, and combinations thereof.

The reaction mixtures of the present invention further comprise at leastone crosslinker. A crosslinker is a monomer with two or morepolymerizable double bonds. Suitable crosslinkers include ethyleneglycol dimethacrylate (“EGDMA”), trimethylolpropane trimethacrylate(“TMPTMA”), glycerol trimethacrylate, polyethylene glycol dimethacrylate(wherein the polyethylene glycol preferably has a molecular weight upto, e.g., about 5000), and other polyacrylate and polymethacrylateesters, such as the end-capped polyoxyethylene polyols described abovecontaining two or more terminal methacrylate moieties. The crosslinkermay be used in the usual amounts, e.g., from about 0.000415 to about0.0156 mole per 100 grams of reactive components in the reactionmixture. Alternatively, if the hydrophilic monomers and/or the siliconecontaining monomers act as the cross-linking agent, the addition of anadditional crosslinking agent to the reaction mixture is optional.Examples of hydrophilic monomers which can act as the crosslinking agentand when present do not require the addition of an additionalcrosslinking agent to the reaction mixture include polyoxyethylenepolyols described above containing two or more terminal methacrylatemoieties.

An example of a silicone containing monomer which can act as acrosslinking agent and, when present, does not require the addition of acrosslinking monomer to the reaction mixture includes α,ω-bismethacryloypropyl polydimethylsiloxane.

The reaction mixtures can also contain multiple crosslinkers dependingon the reaction rate of the hydrophilic component. With very slowreacting hydrophilic components (e.g. VMA, EGVE, DEGVE) crosslinkershaving slow reacting functional groups (e.g. di-vinyl, tri-vinyl,di-allyl, tri-allyl) or a combination of slow reacting functional groupsand fast reacting functional groups (e.g. HEMAVc) can be combined withcrosslinkers having fast reacting functional groups ((meth)acrylates) toimprove the retention of the polymers of the slow-reacting monomers inthe final hydrogel.

In one embodiment the reaction mixture comprises at least twocrosslinkers, at least one first crosslinker having at least two fastreacting groups which will react with the silicone components andhydroxyl alkyl (meth)acrylates and at least one second crosslinkerhaving at least two slow reacting groups which react with the slowreacting hydrophilic monomer. This mixture of fast and slow reactingcrosslinkers provides the final polymer with improved resilience andrecovery, particularly on the surface of the lens. Examples of suitablefirst crosslinkers include those having only (meth)acrylatefunctionality, such as EGDMA, TEGDMA and combinations thereof. Examplesof suitable second crosslinkers include those having only vinylfunctionality, such as triallyl cyanurate (TAC). When mixtures are used,suitable total amounts of all crosslinker in the reactive mixtureinclude between about 0.10% and about 2%, and about 0.1 to about 1% wt,excluding diluent respectively. In another embodiment the total amountof all crosslinker in the reactive mixtures is between 0.7 to about 6.0mmol/100 g of polymerizable components; between about 0.7 to about 4.0mmoles per 100 g of reactive components. The fast and slow reactingcrosslinkers are present in respective amounts of about 0.3 to about 2.0mmol/100 g of polymerizable components and between about 0.4 to about2.0 mmoles per 100 g of reactive components.

The reaction mixture may also comprise at least one UV absorbingcompound. When the silicone hydrogel will be used as an ophthalmicdevice it may be desirable to incorporate a reactive UV absorbingcompound in the reaction mixture so that the resulting silicone hydrogelwill be UV absorbing. Suitable UV absorbers may be derived from2-(2′-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones,2-hydroxyphenyltriazines, oxanilides, cyanoacrylates, salicylates and4-hydroxybenzoates; which may be further reacted to incorporate reactivepolymerizable groups, such as (meth)acrylates. Specific examples of UVabsorbers which include polymerizable groups include2-(2′-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole (Norbloc),5-vinyl and 5-isopropenyl derivatives of2-(2,4-dihydroxyphenyl)-2H-benzotriazole and 4-acrylates or4-methacrylates of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole or2-(2,4-dihydroxyphenyl)-1,3-2H-dibenzotriazole, mixtures thereof and thelike. When a UV absorber is included, it may be included in amountsbetween about 0.5 and about 4 wt %, and in other embodiments betweenabout 1 wt % and about 2 wt %.

A polymerization initiator is preferably included in the reactionmixture. The reaction mixtures of the present invention comprise atleast one thermal, photoinitiator or a mixture thereof. The use ofphotoinitiation provides desirable cure times (time to reach essentiallycomplete cure) of less than about 30 minutes, less than about 20 minutesand in some embodiments less than about 15 minutes. Suitablephotoinitiator systems include aromatic alpha-hydroxy ketones,alkoxyoxybenzoins, acetophenones, acylphosphine oxides, bisacylphosphineoxides, and a tertiary amine plus a diketone, mixtures thereof and thelike. Illustrative examples of photoinitiators are 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide(DMBAPO), bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide (Irgacure819), 2,4,6-trimethylbenzyldiphenyl phosphine oxide and2,4,6-trimethylbenzoyl diphenylphosphine oxide, benzoin methyl ester anda combination of camphorquinone and ethyl 4-(N,N-dimethylamino)benzoate.Commercially available visible light initiator systems include Irgacure819, Irgacure 1700, Irgacure 1800, Irgacure 819, Irgacure 1850 (all fromCiba Specialty Chemicals) and Lucirin TPO initiator (available fromBASF). Commercially available UV photoinitiators include Darocur 1173and Darocur 2959 (Ciba Specialty Chemicals). These and otherphotoinitiators which may be used are disclosed in Volume III,Photoinitiators for Free Radical Cationic & Anionic Photopolymerization,2^(nd) Edition by J. V. Crivello & K. Dietliker; edited by G. Bradley;John Wiley and Sons; New York; 1998, which is incorporated herein byreference. Suitable thermal initiators include lauryl peroxide, benzoylperoxide, isopropyl percarbonate, azobisisobutyronitrile, and the like.The initiator is used in the reaction mixture in effective amounts toinitiate polymerization of the reaction mixture, e.g., from about 0.1 toabout 2 parts by weight per 100 parts of reactive monomer.

The reaction mixture may also comprise at least one diluent or may be“neat”. If a diluent is used, the selected diluents should solubilizethe components in the reactive mixture. It will be appreciated that theproperties of the selected hydrophilic and hydrophobic components mayaffect the properties of the diluents which will provide the desiredcompatibilization. For example, if the reaction mixture contains onlymoderately polar components, diluents having moderate op may be used. Ifhowever, the reaction mixture contains strongly polar components, thediluent may need to have a high δp. However, as the diluent becomes morehydrophobic, processing steps necessary to replace the diluent withwater will require the use of solvents other than water. This mayundesirably increase the complexity and cost of the manufacturingprocess. Thus, it is important to select a diluent which provides thedesired compatibility to the components with the necessary level ofprocessing convenience.

The type and amount of diluent used also effects the properties of theresultant polymer and article. The haze, wettability and modulus of thefinal article may be improved by selecting relatively hydrophobicdiluents and/or decreasing the concentration of diluent used.

Diluents useful in preparing the devices of this invention include polardiluents such as ethers, esters, amides, alcohols, carboxylic acids andcombinations thereof. Amides, carboxylic acids and alcohols arepreferred diluents, and secondary and tertiary alcohols are morepreferred alcohol diluents.

Examples of alcohols useful as diluents for this invention include thosehaving the formula

wherein R, R′ and R″ are independently selected from H, a linear,branched or cyclic monovalent alkyl having 1 to 10 carbons which mayoptionally be substituted with one or more groups including halogens,ethers, esters, aryls, amines, amides, alkenes, alkynes, carboxylicacids, alcohols, aldehydes, ketones or the like, or any two or all threeof R, R′ and R″ can together bond to form one or more cyclic structures,such as alkyl having 1 to 10 carbons which may also be substituted asjust described, with the proviso that no more than one of R, R′ or R″ isH.

It is preferred that R, R′ and R″ are independently selected from H orunsubstituted linear, branched or cyclic alkyl groups having 1 to 7carbons. It is more preferred that R, R′, and R″ are independentlyselected form unsubstituted linear, branched or cyclic alkyl groupshaving 1 to 7 carbons. In certain embodiments, the preferred diluent has4 or more, more preferably 5 or more total carbons, because the highermolecular weight diluents have lower volatility, and lower flammability.When one of the R, R′ and R″ is H, the structure forms a secondaryalcohol. When none of the R, R′ and R″ are H, the structure forms atertiary alcohol. Tertiary alcohols are more preferred than secondaryalcohols. The diluents are preferably inert and easily displaceable bywater when the total number of carbons is five or less.

Examples of useful secondary alcohols include 2-butanol, 2-propanol,menthol, cyclohexanol, cyclopentanol and exonorborneol, 2-pentanol,3-pentanol, 2-hexanol, 3-hexanol, 3-methyl-2-butanol, 2-heptanol,2-octanol, 2-nonanol, 2-decanol, 3-octanol, norborneol, and the like.

Examples of useful tertiary alcohols include tert-butanol, tert-amyl,alcohol, 2-methyl-2-pentanol, 2,3-dimethyl-2-butanol,3-methyl-3-pentanol, 1-methylcyclohexanol, 2-methyl-2-hexanol,3,7-dimethyl-3-octanol, 1-chloro-2-methyl-2-propanol,2-methyl-2-heptanol, 2-methyl-2-octanol, 2-2-methyl-2-nonanol,2-methyl-2-decanol, 3-methyl-3-hexanol, 3-methyl-3-heptanol,4-methyl-4-heptanol, 3-methyl-3-octanol, 4-methyl-4-octanol,3-methyl-3-nonanol, 4-methyl-4-nonanol, 3-methyl-3-octanol,3-ethyl-3-hexanol, 3-methyl-3-heptanol, 4-ethyl-4-heptanol,4-propyl-4-heptanol, 4-isopropyl-4-heptanol, 2,4-dimethyl-2-pentanol,1-methylcyclopentanol, 1-ethylcyclopentanol, 1-ethylcyclopentanol,3-hydroxy-3-methyl-1-butene, 4-hydroxy-4-methyl-1-cyclopentanol,2-phenyl-2-propanol, 2-methoxy-2-methyl-2-propanol2,3,4-trimethyl-3-pentanol, 3,7-dimethyl-3-octanol, 2-phenyl-2-butanol,2-methyl-1-phenyl-2-propanol and 3-ethyl-3-pentanol, and the like.

Examples of useful carboxylic acids include C₂-C₁₆, carboxylic acids,with one or two carboxylic acid groups and optionally a phenyl group.Specific examples include acetic acid, decanoic acid, dodecanoic acid,octanoic acid, benzylic acid, combinations thereof and the like.

A single alcohol or mixtures of two or more of the above-listed alcoholsor two or more alcohols according to the structure above can be used asthe diluent to make the polymer of this invention.

The diluent may be selected from secondary and tertiary alcohols havingat least 4 carbons. Suitable examples include tert-butanol, tert-amylalcohol, 2-butanol, 2-methyl-2-pentanol, 2,3-dimethyl-2-butanol,3-methyl-3-pentanol, 3-ethyl-3-pentanol, 3,7-dimethyl-3-octanol. It hasbeen found secondary and tertiary alcohols having at least 4 carbonatoms, even in relatively low amounts, have a beneficial effect on themodulus of the final polymer. These alcohols, such as t-amyl alcohol,even in amounts as low as 20-20 wt %, can lower the modulus of theresulting polymer by about 20%.

The diluent may also be selected from hexanol, heptanol, octanol,nonanol, decanol, tert-butyl alcohol, 3-methyl-3-pentanol, isopropanol,t amyl alcohol, ethyl lactate, methyl lactate, i-propyl lactate,3,7-dimethyl-3-octanol, dimethyl formamide, dimethyl acetamide, dimethylpropionamide, N methyl pyrrolidinone and mixtures thereof. Additionaldiluents useful for this invention are disclosed in U.S. Pat. No.6,020,445, US20100280146 which is incorporated herein by reference.

In another embodiment the diluent is selected from t-amyl alcohol,3-methyl-3-pentanol, 3,7-dimethyl-3-octanol, decanoic acid, andcombinations thereof and the like.

In one embodiment of the present invention the diluent is water solubleat processing conditions and readily washed out of the lens with waterin a short period of time. Suitable water soluble diluents include1-ethoxy-2-propanol, 1-methyl-2-propanol, t-amyl alcohol, tripropyleneglycol methyl ether, isopropanol, 1-methyl-2-pyrrolidone,N,N-dimethylpropionamide, ethyl lactate, dipropylene glycol methylether, mixtures thereof and the like. The use of a water soluble diluentallows the post molding process to be conducted using water only oraqueous solutions which comprise water as a substantial component.

The diluents may be used in amounts up to about 40% by weight of thetotal of all components in the reactive mixture. In one embodiment thediluent(s) are used in amounts less than about 30% and in another inamounts between about 5 and about 20% by weight of the total of allcomponents in the reactive mixture.

The diluent may also comprise additional components to lower the modulusof the resulting polymers and improve the lens curing efficiency andreducing residuals. Components capable of increasing the viscosity ofthe reactive mixture and/or increasing the degree of hydrogen bondingwith the slow-reacting hydrophilic monomer, are desirable. Suitablecomponents include polyamides, polylactams, such as PVP and copolymersthereof, polyols and polyol containing components such glycerin, boricacid, boric acid glycerol esters, polyalkylene glycols, combinationsthereof and the like.

Suitable polylactams include PVP and copolymers comprising repeatingunits from NVP and hydrophilic monomers. In one embodiment, thepolylactam is selected from, PVP, and the polyamide comprises DMA.

When polyamides or polylactams are used they have a molecular weight ofbetween about K12-K120 (about 3900 to about 3,000,000 Dalton M_(w)) andin some embodiments from K30 to K90 (about 42,000 to about 1,300,000Dalton M_(w)).

Suitable polyalkylene glycols include polyethylene glycol andpolypropylene glycols having molecular weight up to about 350 and insome embodiments less than about 200 gm/mol.

When used, the polyols and polyol containing components are used inamounts less than about 5 wt % and in some embodiments from about 0.2 toabout 5 wt %. The diluents and codiluents of the present invention alsoreduce the residuals remaining in the polymer at the end of thephotocure. This provides lenses with more consistent properties,including diameter. In some embodiments the residual slow-reactinghydrophilic component present at the end of cure are less than about 2wt % of the lens ((wt of residual component/wt of cured polymer)*100%),less than about 1 wt % and in some cases less than about 0.8 wt %. Thereduction in residuals also leads to more consistent lens properties,including lens diameters, which can vary by less than about 0.05 mm.

The reactive mixture may contain additional components such as, but notlimited to, medicinal agents, antimicrobial compounds, reactive tints,pigments, copolymerizable and non-polymerizable dyes, including UVblockers, photochromic compounds, spectral filtering dyes, releaseagents and combinations thereof.

The range of slow-reacting hydrophilic monomer in the reaction mixtureinclude from about 37 to about 70 wt %, from about 39 to about 60 weightpercent. The hydroxyalkyl monomers are present in amounts suitable toprovide a molar ratio of hydroxyalkyl monomer to slow-reactinghydrophilic monomer of about 0.15 to about 0.4. Suitable ranges ofsilicone-containing component(s) are from about 20 to about 60 weight %,and in some embodiments from about 30 to about 55 weight % of thereactive components in the reaction mixture. The reaction mixtures alsocomprise from about 0.2 to about 3 weight % of a crosslinking monomer,from about 0 to about 3 weight % of a UV absorbing monomer, (all basedupon the weight % of all reactive components) and where diluent isdesired, about 20 to about 60 weight % (weight % of all components, bothreactive and non-reactive) of one or more of the claimed diluents. Itshould be appreciated that the foregoing ranges may be combined in anypermutation.

In one embodiment the hydroxyalkyl monomer comprises GMMA and thediluent comprises t-amyl alcohol.

The reaction mixtures of the present invention can be formed by any ofthe methods known to those skilled in the art, such as shaking orstirring, and used to form polymeric articles or devices by knownmethods.

For example, the biomedical devices of the invention may be prepared bymixing reactive components and the diluent(s) with a polymerizationinitiator and curing by appropriate conditions to form a product thatcan be subsequently formed into the appropriate shape by lathing,cutting and the like. Alternatively, the reaction mixture may be placedin a mold and subsequently cured into the appropriate article.

Various processes are known for processing the reaction mixture in theproduction of contact lenses, including spincasting and static casting.Spincasting methods are disclosed in U.S. Pat. Nos. 3,408,429 and3,660,545, and static casting methods are disclosed in U.S. Pat. Nos.4,113,224 and 4,197,266. In one embodiment, the method for producingcontact lenses comprising the polymer of this invention is by the directmolding of the silicone hydrogels, which is economical, and enablesprecise control over the final shape of the hydrated lens. For thismethod, the reaction mixture is placed in a mold having the shape of thefinal desired silicone hydrogel, i.e., water-swollen polymer, and thereaction mixture is subjected to conditions whereby the monomerspolymerize, to thereby produce a polymer/diluent mixture in the shape ofthe final desired product.

Referring to FIG. 1, a diagram is illustrated of an ophthalmic lens 100,such as a contact lens, and mold parts 101-102 used to form theophthalmic lens 100. In some embodiments, the mold parts include a backsurface mold part 101 and a front surface mold part 102. As used herein,the term “front surface mold part” refers to the mold part whose concavesurface 104 is a lens forming surface used to form the front surface ofthe ophthalmic lens. Similarly, the term “back surface mold part” refersto the mold part 101 whose convex surface 105 forms a lens formingsurface, which will form the back surface of the ophthalmic lens 100. Insome embodiments, mold parts 101 and 102 are of a concavo-convex shape,preferably including planar annular flanges, which surround thecircumference of the uppermost edges of the concavo-convex regions ofthe mold parts 101-102.

Typically, the mold parts 101-102 are arrayed as a “sandwich”. The frontsurface mold part 102 is on the bottom, with the concave surface 104 ofthe mold part facing upwards. The back surface mold part 101 can bedisposed symmetrically on top of the front surface mold part 102, withthe convex surface 105 of the back surface mold part 101 projectingpartially into the concave region of the front surface mold part 102. Inone embodiment, the back surface mold part 101 is dimensioned such thatthe convex surface 105 thereof engages the outer edge of the concavesurface 104 of the front mold part 102 throughout its circumference,thereby cooperating to form a sealed mold cavity in which the ophthalmiclens 100 is formed.

In some embodiments, the mold parts 101-102 are fashioned ofthermoplastic and are transparent to polymerization-initiating actinicradiation, by which is meant that at least some, and in some embodimentsall, radiation of an intensity and wavelength effective to initiatepolymerization of the reaction mixture in the mold cavity can passthrough the mold parts 101-102.

For example, thermoplastics suitable for making the mold parts caninclude: polystyrene; polyvinylchloride; polyolefin, such aspolyethylene and polypropylene; copolymers or mixtures of styrene withacrylonitrile or butadiene, polyacrylonitrile, polyamides, polyesters,cyclic olefin copolymers such as Topas available from Ticona or Zeonoravailable from Zeon, copolymers and blends of any of the foregoing, orother known material.

Following polymerization of the reaction mixture to form a lens 100, thelens surface 103 will typically adhere to the mold part surface 104. Thesteps of the present invention facilitate release of the surface 103from the mold part surface.

The first mold part 101 can be separated from the second mold part 102in a demolding process. In some embodiments, the lens 100 will haveadhered to the second mold part 102 (i.e. the front curve mold part)during the cure process and remain with the second mold part 102 afterseparation until the lens 100 has been released from the front curvemold part 102. In other embodiments, the lens 100 can adhere to thefirst mold part 101.

The lens 100 may be removed from the mold part may be released from themold by any process, including contacting with a solvent or dry release.In one embodiment, the lens 100 and the mold part to which it is adheredafter demolding are contacted with an aqueous solution. The aqueoussolution can be heated to any temperature below the boiling point of theaqueous solution, and preferably at least about 10° C. below the boilingpoint of the high boiling point diluent. In some embodiments the aqueoussolution is heated to a temperature which is at least about 10° C. lowerthan the boiling point of the diluent having the lowest boiling point.Heating can be accomplished with a heat exchange unit to minimize thepossibility of explosion, or by any other feasible means or apparatusfor heating a liquid.

As used herein, processing includes the steps of removing the lens fromthe mold and removing or exchanging the diluent with an aqueoussolution. The steps may be done separately, or in a single step orstage. The processing temperature may be any temperatures between about30° C. and the boiling point of the aqueous solutions, in someembodiments between about 30° C. and about 95° C., and in someembodiments between about 50° C. and about 95° C.

The aqueous solution is primarily water. In some embodiments, theaqueous solution is at least about 70 wt % water, and in otherembodiments at least about 90 weight % water and in other embodiments atleast about 95%. The aqueous solution may also be a contact lenspackaging solution such as borate buffered saline solution, sodiumborate solutions, sodium bicarbonate solutions and the like. The aqueoussolution may also include additives, such as surfactants, preservatives,release aids, antibacterial agents, pharmaceutical and nutriceuticalcomponents, lubricants, wetting agents, salts, buffers, mixtures thereofand the like. Specific examples of additives which may be included inthe aqueous solution include Tween® 80, which is polyoxyethylenesorbitan monooleate, Tyloxapol, octylphenoxy (oxyethylene) ethanol,amphoteric 10), EDTA, sorbic acid, DYMED, chlorhexadine gluconate,hydrogen peroxide, thimerosal, polyquad, polyhexamethylene biguanide,mixtures thereof and the like. Where various zones are used, differentadditives may be included in different zones. In some embodiments,additives can be added to the hydration solution in amounts varyingbetween 0.01% and 10% by weight, but cumulatively less than about 10% byweight.

Exposure of the ophthalmic lens 100 to the aqueous solution can beaccomplished by any method, such as washing, spraying, soaking,submerging, or any combination of the aforementioned. For example, insome embodiments, the lens 100 can be washed with an aqueous solutioncomprising deionized water in a hydration tower.

In embodiments using a hydration tower, front curve mold parts 102containing lenses 100 can be placed in pallets or trays and stackedvertically. The aqueous solution can be introduced at the top of thestack of lenses 100 so that the solution will flow downwardly over thelenses 100. The solution can also be introduced at various positionsalong the tower. In some embodiments, the trays can be moved upwardlyallowing the lenses 100 to be exposed to increasingly fresher solution.

In other embodiments, the ophthalmic lenses 100 are soaked or submergedin the aqueous solution.

The contacting step can last up to about 12 hours, in some embodimentsup to about 2 hours and in other embodiments from about 2 minutes toabout 2 hours; however, the length of the contacting step depends uponthe lens materials, including any additives, the materials that are usedfor the solutions or solvents, and the temperatures of the solutions.Sufficient treatment times typically shrink the contact lens and releasethe lens from the mold part. Longer contacting times will providegreater leaching.

The volume of aqueous solution used may be any amount greater than about1 ml/lens and in some embodiments greater than about 5 ml/lens.

In some methods, after separation or demolding, the lenses on the frontcurves, which may be part of a frame, are mated with individual concaveslotted cups to receive the contact lenses when they release from thefront curves. The cups can be part of a tray. Examples can include trayswith 32 lenses each, and 20 trays that can be accumulated into amagazine.

According to another embodiment of the present invention the lenses aresubmerged in the aqueous solution. In one embodiment, magazines can beaccumulated and then lowered into tanks containing the aqueous solution.The aqueous solution may also include other additives as describedabove.

As used herein clarity means substantially free from visible haze. Clearlenses have a haze value of less than about 100%, less than about 50%,less than about 20%, and less than about 15%.

The contact lenses of the present invention may further comprise modulusvalues less than about 150, about 120 and about 100 psi.

The biomedical devices, and particularly ophthalmic devices and contactlenses have average contact angles (advancing) which are less than about80°, less than about 70° and less than about 60°. In some embodimentsthe articles of the present invention have combinations of the abovedescribed oxygen permeability, water content and contact angle. Allcombinations of the above ranges are deemed to be within the presentinvention.

Hansen Solubility Parameter

The Hansen solubility parameter, op may be calculated by using the groupcontribution method described in Barton, CRC Handbook of SolubilityPar., 1st. Ed. 1983, page 85-87 and using Tables 13, 14.

Haze Measurement

Haze is measured by placing a hydrated test lens in borate bufferedsaline in a clear 20×40×10 mm glass cell at ambient temperature above aflat black background, illuminating from below with a fiber optic lamp(Dolan-Jenner PL-900 fiber optic light. fiber optic light with 0.5″diameter light guide set at a power setting of 4-5.4) at an angle 66°normal to the lens cell, and capturing an image of the lens from above,normal to the lens cell with a video camera (DVC 1300C:19130 RGB camerawith Navitar TV Zoom 7000 zoom lens) placed 14 mm above the lensplatform. The background scatter is subtracted from the scatter of thelens by subtracting an image of a blank cell using EPIX XCAP V 2.2software. The subtracted scattered light image is quantitativelyanalyzed, by integrating over the central 10 mm of the lens, and thencomparing to a −1.00 diopter CSI Thin Lens®, which is arbitrarily set ata haze value of 100, with no lens set as a haze value of 0. Five lensesare analyzed and the results are averaged to generate a haze value as apercentage of the standard CSI lens. Lenses have haze levels of lessthan about 150% (of CSI as set forth above) and in some cases less thanabout 100%. Alternatively, instead of a −1.00 diopter CSI Thin Lenses®,a series of aqueous dispersions of stock latex spheres (commerciallyavailable as 0.49 μm Polystyene Latex Spheres—Certified Nanosphere SizeStandards from Ted Pella, Inc., Product Number 610-30) can be used asstandards. A series of calibration samples were prepared in deionizedwater. Each solution of varying concentration was placed in a cuvette (2mm path length) and the solution haze was measured using the abovemethod.

Concentration Solution (wt % × 10⁻⁴) Mean GS 1 10.0 533 2 6.9 439 3 5.0379 4 4.0 229 5 2.0 172 6 0.7 138 Mean GS = mean gray scaleA corrective factor was derived by dividing the slope of the plot ofMean GS against the concentration (47.1) by the slope of anexperimentally obtained standard curve, and multiplying this ratio timesmeasured scatter values for lenses to obtain GS values.

“CSI haze value” may be calculated as follows:

CSI haze value=100×(GS−BS)/(217−BS)

Where GS is gray scale and BS is background scatter.

Water Content

The water content of contact lenses was measured as follows: Three setsof three lenses are allowed to sit in packing solution for 24 hours.Each lens is blotted with damp wipes and weighed. The lenses are driedat 60° C. for four hours at a pressure of 0.4 inches Hg or less. Thedried lenses are weighed. The water content is calculated as follows:

${\% \mspace{14mu} {water}\mspace{14mu} {content}} = {\frac{\left( {{{wet}\mspace{14mu} {weight}} - {{dry}\mspace{14mu} {weight}}} \right)}{{wet}\mspace{14mu} {weight}} \times 100}$

The average and standard deviation of the water content are calculatedfor the samples and are reported.

Modulus

Modulus is measured by using the crosshead of a constant rate ofmovement type tensile testing machine equipped with a load cell that islowered to the initial gauge height. A suitable testing machine includesan Instron model 1122. A dog-bone shaped sample having a 0.522 inchlength, 0.276 inch “ear” width and 0.213 inch “neck” width is loadedinto the grips and elongated at a constant rate of strain of 2 in/min.until it breaks. The initial gauge length of the sample (Lo) and samplelength at break (Lf) are measured. Twelve specimens of each compositionare measured and the average is reported. Percent elongation is=[(Lf−Lo)/Lo]×100. Tensile modulus is measured at the initial linearportion of the stress/strain curve.

Advancing Contact Angle

All contact angles reported herein are advancing contact angles. Theadvancing contact angle was measured as follows. Four samples from eachset were prepared by cutting out a center strip from the lensapproximately 5 mm in width and equilibrated in packing solution. Thewetting force between the lens surface and borate buffered saline ismeasured at 23° C. using a Wilhelmy microbalance while the sample isbeing immersed into or pulled out of the saline. The following equationis used

F=2γp cos θ or θ=cos⁻¹(F/2γp)

where F is the wetting force, γ is the surface tension of the probeliquid, p is the perimeter of the sample at the meniscus and θ is thecontact angle. The advancing contact angle is obtained from the portionof the wetting experiment where the sample is being immersed into thepacking solution. Each sample was cycled four times and the results wereaveraged to obtain the advancing contact angles for the lens.

Oxygen Permeability (Dk)

The Dk is measured as follows. Lenses are positioned on a polarographicoxygen sensor consisting of a 4 mm diameter gold cathode and a silverring anode then covered on the upper side with a mesh support. The lensis exposed to an atmosphere of humidified 2.1% O₂. The oxygen thatdiffuses through the lens is measured by the sensor. Lenses are eitherstacked on top of each other to increase the thickness or a thicker lensis used. The L/Dk of 4 samples with significantly different thicknessvalues are measured and plotted against the thickness. The inverse ofthe regressed slope is the Dk of the sample. The reference values arethose measured on commercially available contact lenses using thismethod. Balafilcon A lenses available from Bausch & Lomb give ameasurement of approx. 79 barrer. Etafilcon lenses give a measurement of20 to 25 barrer. (1 barrer=10⁻¹⁰ (cm³ of gas×cm²)/(cm³ of polymer×sec×cmHg)).

Lysozyme Uptake

Lysozyme uptake was measured as follows: The lysozyme solution used forthe lysozyme uptake testing contained lysozyme from chicken egg white(Sigma, L7651) solubilized at a concentration of 2 mg/ml in phosphatesaline buffer supplemented by Sodium bicarbonate at 1.37 g/l andD-Glucose at 0.1 g/l.

Three lenses for each example were tested using each protein solution,and three were tested using PBS (phosphate buffered saline) as a controlsolution. The test lenses were blotted on sterile gauze to removepacking solution and aseptically transferred, using sterile forceps,into sterile, 24 well cell culture plates (one lens per well) each wellcontaining 2 ml of lysozyme solution. Each lens was fully immersed inthe solution. 2 ml of the lysozyme solution was placed in a well withouta contact lens as a control.

The plates containing the lenses and the control plates containing onlyprotein solution and the lenses in the PBS, were parafilmed to preventevaporation and dehydration, placed onto an orbital shaker and incubatedat 35° C., with agitation at 100 rpm for 72 hours. After the 72 hourincubation period the lenses were rinsed 3 to 5 times by dipping lensesinto three (3) separate vials containing approximately 200 ml volume ofPBS. The lenses were blotted on a paper towel to remove excess PBSsolution and transferred into sterile conical tubes (1 lens per tube),each tube containing a volume of PBS determined based upon an estimateof lysozyme uptake expected based upon on each lens composition. Thelysozyme concentration in each tube to be tested needs to be within thealbumin standards range as described by the manufacturer (0.05 microgramto 30 micrograms). Samples known to uptake a level of lysozyme lowerthan 100 μg per lens were diluted 5 times. Samples known to uptakelevels of lysozyme higher than 500 μg per lens (such as etafilcon Alenses) are diluted 20 times.

1 ml aliquot of PBS was used for all samples other than etafilcon. 20 mlwere used for etafilcon A lens. Each control lens was identicallyprocessed, except that the well plates contained PBS instead of lysozymesolution.

Lysozyme uptake was determined using on-lens bicinchoninic acid methodusing QP-BCA kit (Sigma, QP-BCA) following the procedure described bythe manufacturer (the standards prep is described in the kit) and iscalculated by subtracting the optical density measured on PBS soakedlenses (background) from the optical density determined on lenses soakedin lysozyme solution.

Optical density was measured using a SynergyII Micro-plate readercapable for reading optical density at 562 nm.

Lipocalin uptake was measured using the following solution and method.The lipocalin solution contained B Lactoglobulin (Lipocalin) from bovinemilk (Sigma, L3908) solubilized at a concentration of 2 mg/ml inphosphate saline buffer (Sigma, D8662) supplemented by sodiumbicarbonate at 1.37 g/l and D-Glucose at 0.1 g/l.

Three lenses for each example were tested using the lipocalin solution,and three were tested using PBS as a control solution. The test lenseswere blotted on sterile gauze to remove packing solution and asepticallytransferred, using sterile forceps, into sterile, 24 well cell cultureplates (one lens per well) each well containing 2 ml of lipocalinsolution. Each lens was fully immersed in the solution. Control lenseswere prepared using PBS as soak solution instead of lipocalin. Theplates containing the lenses immersed in lipocalin solution as well asplates containing control lenses immersed in PBS, were parafilmed toprevent evaporation and dehydration, placed onto an orbital shaker andincubated at 35° C., with agitation at 100 rpm for 72 hours. After the72 hour incubation period the lenses were rinsed 3 to 5 times by dippinglenses into three (3) separate vials containing approximately 200 mlvolume of PBS. The lenses were blotted on a paper towel to remove excessPBS solution and transferred into sterile 24 well plates each wellcontaining 1 ml of PBS solution.

Lipocalin uptake was determined using on-lens bicinchoninic acid methodusing QP-BCA kit (Sigma, QP-BCA) following the procedure described bythe manufacturer (the standards prep is described in the kit) and iscalculated by subtracting the optical density measured on PBS soakedlenses (background) from the optical density determined on lenses soakedin lipocalin solution. Optical density was measured using a SynergyIIMicro-plate reader capable for reading optical density at 562 nm.

Mucin uptake was measured using the following solution and method. TheMucin solution contained Mucins from bovine submaxillary glands (Sigma,M3895-type 1-S) solubilized at a concentration of 2 mg/ml in phosphatesaline buffer (Sigma, D8662) supplemented by sodium bicarbonate at 1.37g/l and D-Glucose at 0.1 g/l.

Three lenses for each example were tested using Mucin solution, andthree were tested using PBS as a control solution. The test lenses wereblotted on sterile gauze to remove packing solution and asepticallytransferred, using sterile forceps, into sterile, 24 well cell cultureplates (one lens per well) each well containing 2 ml of Mucin solution.Each lens was fully immersed in the solution. Control lenses wereprepared using PBS as soak solution instead of lipocalin.

The plates containing the lenses immersed in Mucin as well as platescontaining control lenses immersed in PBS were parafilmed to preventevaporation and dehydration, placed onto an orbital shaker and incubatedat 35° C., with agitation at 100 rpm for 72 hours. After the 72 hourincubation period the lenses were rinsed 3 to 5 times by dipping lensesinto three (3) separate vials containing approximately 200 ml volume ofPBS. The lenses were blotted on a paper towel to remove excess PBSsolution and transferred into sterile 24 well plates each wellcontaining 1 ml of PBS solution.

Mucin uptake was determined using on-lens bicinchoninic acid methodusing QP-BCA kit (Sigma, QP-BCA) following the procedure described bythe manufacturer (the standards prep is described in the kit) and iscalculated by subtracting the optical density measured on PBS soakedlenses (background) from the optical density determined on lenses soakedin Mucin solution. Optical density was measured using a SynergyIIMicro-plate reader capable for reading optical density at 562 nm.

Kinetics

The kinetic half lives for components may be determined as follows. Thecomponents for each kinetics example were weighed into a 20 mL amberborosilicate glass scintillation vial (Wheaton 320 brand; Catalogue#80076-576, or equivalent). Vials were capped (using PTFE lined greencap, Qorpak; Supplier #5205/100, Catalogue #16161-213) and rolled on jarroller until all solids were dissolved and a homogeneous mixtures wereobtained.

Degas

Reactive monomer mixes were degassed under vacuum, under yellow lightfor 7-10 minutes, and back-filling with nitrogen after breaking vacuum.Vials were quickly capped and placed in compartment 1 of a twocompartment nitrogen cure box, via the gated aperature, 7, as shown inFIG. 2. The conditions in compartment 1 were room temperature and <0.5%oxygen (using continuous nitrogen purge).

Nitrogen Cure Box—Compartment 2

The oxygen level in both compartments was maintained bycontinuous/constant nitrogen purge. The temperature in Compartment 2 wasmaintained by a heater (COY, Laboratory Products Inc.). The nitrogencure box was allowed to equilibrate for a minimum of 4 hours prior toperforming each kinetics study. The degassed reactive mixture (intightly capped amber vial) was placed in compartment 1 during theequilibration period.

Light Source and Intensity Setting

As depicted in FIG. 3, 2 fluorescent light fixtures (Lithonia LightingFluorescent Luminaire (Gas Tube Luminaire), 60 cm×10.5 cm) each equippedwith 2 fluorescent lamps (Philips TLK 40W/03, 58 cm) were arranged inparallel. The cure intensity was attenuated by adjusting the height ofthe shelf (shown in FIGS. 2 and 3) relative to the light source. Theintensity at a given shelf height was measured by placing the sensor ofa calibrated radiometer/photometer on the mirrored surface, consistentwith the position of the sample, as shown in FIG. 3. The sensor wasplaced directly under the space between the 2^(nd) and 3^(rd) lamps inthe 4 lamps arrangement.

Using a calibrated analytical balance (4 decimal places) the weight of aclear borosilicate glass scintillation vial (Wheaton 986541) with cap(white cap with polyethylene insert) was determined. The vial with capwas transferred to Compartment 1 of the Nitrogen Cure Box. The cap wasunscrewed and using a calibrated 10-100 μL Eppendorf Pipet, 100 μL ofthe Reactive Monomer Mixture was transferred into the vial. The vial wastightly capped, quickly moved into Compartment 2, via door 6, and placedon the mirrored surface 4, as shown in FIG. 2. The sample was placeddirectly under the space between the 2^(nd) and 3^(rd) lamps in the 4lamps arrangement. The light source 3, was turned on and the sample wasexposed for a specified time period. Although the light source was setat 4-5 mW/cm², the actual intensity reaching the sample is 0.7-1.3mW/cm², due the cap on the sample glass vials. After exposure, the lightsource 3, was turned off and the vial (with cap) was re-weighed todetermine the sample weight by difference. Using a calibrated 500-5000μL Eppendorf Pipet, 10 mL HPLC grade methanol was added to the vial.

Aliquots (100 μL) of the Reactive Monomer Mixture were pipetted intoseparate borosilicate glass scintillation vials and the above proceduredescribed above was performed to generate samples at the followingminimum time points (minutes): 0, 0.25, 0.50, 0.75, 1, 2, 4, 6, 8, 10.

Cured polymers were extracted in methanol overnight by gently shaking atroom temperature.

Extracts were analyzed for residual components by High PerformanceLiquid Chromatography with UV detection (HPLC/UV) using the followingprocedures.

Quantitation of the mPDMS in the extracts was performed against externalcalibration standards (about 6-11, using the response of the n=6oligomer), typically covering the range of 1 μg/mL-800 μg/mL. If theconcentrations of mPDMS in the extracts were outside the calibrationrange, the extracts were diluted with methanol to render concentrationswithin the calibration range for more accurate quantitation.

Chromatographic Conditions

Column: Agilent Zorbax Eclipse XDB18, 4.6×50 mm×1.8 μm

Column Temperature: 30° C. UV Detector: 217 nm Injection Volume: 20 μLMobile Phase Eluent A: De-ionized Eluent B: Acetonitrile Eluent C:Isopropanol

Flow Rate: 1 mL/min

Time (mins) % A % B % C 0.0 50 48 2 0.5 50 48 2 2.0 0 60 40 5.0 0 60 405.1 0 30 70 8.0 0 30 70 8.1 50 48 2 10.0 50 48 2Quantitation of the components in the extracts other than mPDMS wasperformed against external calibration standards (about 6-11) for eachcomponent, typically covering the range of 1 μg/mL-800 μg/mL. If theconcentrations of components in the extracts were outside thecalibration range, the extracts were appropriately diluted with methanolto render concentrations within the calibration range for more accuratequantitation.

Chromatographic Conditions

Column: Agilent Zorbax Eclipse Plus 18, 4.6×75 mm×1.8 μm

Column Temperature: 30° C. UV Detector: 217 nm Injection Volume: 5 μLMobile Phase

Eluent A: De-ionized water with 0.05% H₃PO₄Eluent B: Acetonitrile with 0.05% H₃PO₄

Eluent C: Methanol

Flow Rate: 1 mL/min

Time (mins) % A % B % C 0 95 5 0 5 95 5 0 15 0 100 0 23 0 100 0 24 0 3070 28 0 30 70 29 95 5 0 35 95 5 0

Calculations

1. At each time point the following values are determined:The concentration (μg/mL) of each component in the sample extract.The concentration of each component in the sample extract, expressed asa percent of the sample weight as follows:

% Component=[(μg/mL*Volume of Extract*Dilution Factor*10⁻⁶ g/μg)/(gSample Weight)]*100

The percent unreacted component present, expressed as a percent relativeto T₀ (where T₀ represented 100% unreacted component)

% at T _(x)=(% Measured at T _(x)/% Measured at T ₀)*100

-   -   2. Using the % Component calculated above, the concentration of        each component in μmoles/g, is calculated as follows:

μmoles/g=(% Component*10³)/(Molecular Weight of Component)

-   -   3. Using the concentration of each component determined in        μmoles/g in step 2, the concentration at Time_(x) was expressed        as

Log [A _(x) ]/[A _(o)],

where [A_(x)] is the concentration of component A at x minutes and[A_(o)] is the concentration of component A at 0 minutes (T₀)

-   -   The expression Log [A_(x)]/[A_(o)] was determined for each time        point.        First order kinetics were assumed for determining both the        polymerization kinetics rate and half life for each component.        The following equations were used for calculating polymerization        rate

Log [A]/[A ₀ ]=−kt/2.303

and half life

ln [A ₀]/[0.5A ₀ ]=kt _(1/2) or t _(1/2)=0.693/k

For each component, a plot of Log [A_(x)]/[A₀] versus time (minutes) wasgenerated. Typically, the data points (x, y) that best correspond tolinear growth (shorter cure times) were plotted and the data were fittedto a linear equation.

Using the slope, the kinetic rate constant (k) of each component wasevaluated from the following equation:

k(minute⁻¹)=Slope*−2.303

The half-life (minutes) of each component was evaluated from thefollowing equation:

t _(1/2)=0.693/k

The evaluated half-life for each component was compared to the datagenerated for the percent of each component relative to T₀, at each timepoint. Typically for each component, the time taken to attain 50%consumption was close to the half-life based on 1^(st) order kinetics Incases where the two were significantly different (typically about 30%for half-life of less than about 1 minute, 25% for half-life less thanabout 2.5 minutes but greater than 1 minute and 20% for half-lifegreater than 2.5 minutes), the data points (x, y) were re-evaluated togenerate kinetic rate constants (k) which would provide half-lives(based on 1^(st) order considerations) more consistent (within 20%) withthe measured values.

The Examples below further describe this invention, but do not limit theinvention. They are meant only to suggest a method of practicing theinvention. Those knowledgeable in the field of contact lenses as well asother specialties may find other methods of practicing the invention.However, those methods are deemed to be within the scope of thisinvention.

Some of the other materials that are employed in the Examples areidentified as follows:

EXAMPLES

The following abbreviations are used in the examples below:

FC Front mold curvesBC Back mold curvesSiMAA(3-methacryloxy-2-hydroxypropoxy)propyl-bis(trimethylsiloxy)methylsilane(Also known as SiGMA)

DMA N,N-dimethylacrylamide

HEMA 2-hydroxyethyl methacrylateHEAA hydroxyethylacrylamideHBMA 2-hydroxybutyl methacrylate, prepared as in Synthetic Example 1HPMA 2-hydroxypropyl methacrylate (ACROS)DMHEMA dimethylhydroxyethylmethacrylate, prepared as in SyntheticExample 2mPDMS 800-1000 MW (M_(n)) monomethacryloxypropyl terminated mono-n-butylterminated polydimethylsiloxaneOH-mPDMSα-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,(MW 612 g/mol), prepared as in Example 8 of US20100249356 A1Norbloc 2-(2′-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazoleD3O 3,7-dimethyl-3-octanolIPA isopropyl alcoholTAC triallylcyanurateTEGDMA tetraethyleneglycol dimethacrylateTRIS 3-methacryloxypropyltris(trimethylsiloxy)silaneacPDMS bis-3-methacryloxy-2-hydroxypropyloxypropylpolydimethylsiloxane (MW about 1000 g/mole)CGI 819 bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxideEtOAc ethyl acetateDA decanoic acidMacromer A Described in Example 25 of U.S. Pat. No. 6,943,203GMMA 2,3-dihydroxypropyl methacrylateTAA t-amyl alcoholETOH ethanolSA-2 N-(2,3-dihydroxypropane)-N′-(propyl tetra(dimethylsiloxy)dimethylbutylsilane)acrylamide, as shown in Formula XI

NVP N-vinylpyrrolidone

PVP poly(N-vinylpyrrolidone)VINAL an ionic amide containing vinyl ether having the structure

and prepared in Synthetic Preparation 1.BAE (Boric Acid Ester) was formed as follows:

1.24 parts of a 5% (wt) solution of ethylenediaminetetraacetic acid, 299parts (wt) glycerol and 100 parts (wt) boric acid were added to areaction flask. The mixture was heated with stirring to 90° C. Vacuumwas applied to reduce the pressure to less than 6 torr as the mixturewas stirred for 155 minutes, with removal of water vapor. The pressurewas reduced to less than 2 torr and the reaction was continued for 2hours, or longer as needed until the % water of the mixture was reducedto less than 0.2% using a Karl Fischer test.

BAGE (Boric Acid Glycerol Ester) was formed as follows:

To BAE prepared as described above was added 624 parts (wt) glycerolwith stirring for 60 minutes at 35-40° C.

Comparative Example

A reaction mixture formed by mixing the components listed in Table 1with a diluent (50% ethanol/50% ethyl acetate) in mixtures of 80%reactive components/20% diluents. The reaction mixture was degassed byapplying vacuum at ambient temperature for about 17(±3) minutes. Thereaction mixture was then dosed into thermoplastic contact lens molds(front curves made from Zeonor, and back curves from polypropylene), andcured for about 20 minutes at 45° C., under a nitrogen atmosphere, usingPhilips TL 20W/03T fluorescent bulbs and 4-5 mW/cm². The resultinglenses were released from the front curve molds using deionized water atambient temperature transferred into vials containing borate bufferedsaline for at least 24 hours and then autoclaved at 122° C. for 30minutes. The resulting lenses were hazy, but felt lubricious when rubbedbetween the thumb and forefinger.

The percent haze was measured and the results are listed in Table 1.

Examples 1 and 2

The Comparative Example was repeated, except that the HEMA was increasedand NVP was decreased as shown in Table 1, below. The lenses werereleased from the front curve mold using mechanical force and extractedin di-ionized water at ambient temperature and pressure. Both lensesfelt lubricious when rubbed between the thumb and index finger. Thepercent haze was measured for both lenses and is shown in Table 1,below.

TABLE 1 Ex. # Ex. 1 Ex. 2 CE1 Component Wt % Wt % Wt % mPDMS 1000 20 2020 TRIS 20 20 20 NVP 47 39.25 52 HEMA 10.75 18.5 5.75 CGI 819 2 2 2TEGDMA 0.25 0.25 0.25 % Haze 22 15 259

The lenses of the Comparative Example 1 were very hazy, displaying ahaze value of 259%, while the lenses of Examples 1 and 2 haddramatically improved haze values of 22% and 15% respectively. Thelenses of the Comparative Example were so hazy that they could not beused as contact lenses.

Examples 3-13

A series of lens formulations were formed from the following components:

38.5 wt % mPDMS58.25 wt % NVP and HEMA, combined (individual amounts shown in Table 2).

2% Norbloc 1 wt % TEGDMA 0.25 CGI 819

The reactive components were mixed with a diluents (50% TAA/50% DA) in aratio of 80 wt % reactive components:20 wt % diluent. The reactionmixtures were cast and cured into lenses following the process describedin Examples 1 and 2. Lenses were released in 50/50 IPA/water, extractedin 70/30 IPA/water and subsequently equilibrated in de-ionized water.Lenses were transferred into vials containing borate buffered saline forat least 24 hours and then autoclaved at 122° C. for 30 minutes. Lensproperties were measured and are reported in Table 2, below.

TABLE 2 [HEMA] [NVP] HEMA: Mechanicals Ex# wt % wt % NVP¹ % H₂O % HazeDCA Mod. (psi) Elong. (%) Dk AC:RC 3 5.75 52.50 0.0935 61.8 (0.1) 479(8)   62 (4)  53.2 (2.5) 162.6 (34.8) 102.1 54 4 6.75 51.50 0.112 61.4(0.2) 464 (20)   54 (6)  57.9 (3.6) 187.3 (51.1) 98.3 62 5 7.75 50.500.131 58.9 (0.1) 233 (59)   58 (5)  61.6 (5.2) 189.8 (50.4) 102.1 69 68.75 49.50 0.152 58.2 (0.2)  17 (17)   60 (5)  67.0 (3.9) 157.4 (43.8)100.3 77 7 9.75 48.50 0.172 60.0 (0.3)  5 (1) 59.5 (5)  70.6 (4) 159.2(47.5) 96.3 85 8 10.75 47.50 0.193 59.1 (0.0)  8 (0)   60 (7)  79.9(1.9) 196.2 (24.6) 89.1 92 9 15.75 42.50 0.316 55.7 (0.0)  11 (1)   70(7)  97.5 (4.2) 192.8 (39.2) 83.5 131 10 18.75 39.50 0.405 51.7 (0.1) 16 (2) * NW 102.5 (4.0) 180.6 (38.6) 77.3 154 11 21.75 36.50 0.509 49.7(0.1)  44 (2) * NW 115.9 (3.1) 206.3 (53.8) 62.3 177 12 25.75 32.500.677 46.5 (0.3) 112 (4) * NW 119.6 (6.9) 199.5 (46.6) 63.2 208 13 29.0029.25 0.839 40.7 (0.2) 186 (3) * NW 138.8 (6.7) 190.7 (32.4) 59.7 233¹molar ratio AC:RC = mmol ancillary components/100 gm reactive mixture *NW = Not Wettable

As can be seen from Examples 3-5, lenses made from reaction mixturescontaining less than about 8 wt % HEMA displayed very high haze values(>about 200%) which are unsuitable for a contact lens, while lenseshaving between 10 and 22 wt % HEMA displayed exceptionally good hazevalues (9-44%). It should also be noted that lenses formed from reactionmixtures having less than about 40 wt % NVP displayed poorwettabilities, and actually repelled water. Examples 3 through 13 alsoshow that as the amount of HEMA is increased, the Dk of the lensesdecrease by as much as 40% (comparing Example 6 to Example 13), eventhough the amount of the silicone-containing component, and the %silicon (12.089) in the reactive mixture remained the same.

The data from Table 2 is plotted in FIG. 4, and shows that as the ratioof ancillary components to reactive mixture decreases, the oxygenpermeability of the silicone hydrogel increases.

Examples 14-16

A reaction mixture was formed by mixing the components listed in Table 3with 20 wt % of a 50:50 mixture of TAA and decanoic acid and degassed byapplying vacuum at ambient temperature for about 17(±3) minutes. Thereaction mixture (75 μL) was then dosed at room temperature and <0.1%O₂, into thermoplastic contact lens molds (FC—Zeonor, BC Polypropylene)which had been degassed in N₂ box at RT (Compartment 1, FIG. 1) for aminimum of 12 hours prior to dosing. The BC was placed on the FC moldand the lenses were moved into Compartment 2 and cured for 20 minutes,at an intensity of 4-5 mW/cm², <0.1% O₂, and 62-65° C.

Lenses were released in 50/50 IPA/water, extracted in 70/30 IPA/waterand subsequently equilibrated in de-ionized water. Lenses weretransferred into vials containing borate buffered saline for at least 24hours and then autoclaved at 122° C. for 30 minutes. Lens propertieswere measured and are reported in Table 4, below.

TABLE 3 Component 14 15 16 17 mPDMS 1000 20.50 20.50 20.50 20.50 NVP65.50 70.50 72.50 0 DMA 0 0 0 72.5 HEMA 10.75 5.75 3.25 3.25 TEGDMA 1.001.00 1.50 1.50 Norblock 2.00 2.00 2.00 2.00 CGI 819 0.25 0.25 0.25 0.25

TABLE 4 Mechanicals Mod. Elong. Ex. # % H₂O % Haze DCA (psi) (%) DkAC:RM 14 70.5  4 (1) 55 (6)  51.0 208.7 48.9 92 (0.2) (6.3) (37.5) 1578.1  6 (0) 50 (6)  30.8 224.9 58.1 54 (0.1) (2.6) (29.6) 16 77.9 30 (1)51 (7)  29.7 172.0 61.0 36 (0.3) (2.2) (36.0) CE2 68.4  1 (0) 99 (4)138.6 118.6 37.8 769 (0.3) (3.5) (32.3)

The DMA in Comparative Example 2 is an intermediate reacting monomer. Ascan be seen from the AC:RM ratio replacing the NVP with DMAsubstantially decreases the Dk of the resulting lenses compared to thoseof Comparative Example 2.

Examples 17-22

Example 8 was repeated, except that the amount of hydroxylalkyl(meth)acrylate and NVP were varied to provide molar ratios of thehydroxylalkyl (meth)acrylate:NVP of about 0.2. GMMA has two hydroxylgroups. Accordingly, formulations having two different concentrations ofGMMA were prepared, Example 21 (13.23 wt % GMMA, 0.408 ratio, countingboth hydroxyls) and Example 22 (6.62 wt % GMMA, 0.204, counting twohydroxyl).

Examples 20 and 21 produces hazy reaction mixtures which were not curedinto lenses. Examples 17-19 and 22 produced clear reaction mixtureswhich were cast into lenses following the procedure described in Example8. Lens properties were measured. The formulations and lens propertiesare shown in Table 5, below.

Comparing Examples 21 and 22, it can be seen that when the molar amountof GMMA was adjusted to account for both hydroxyls, clear lenses wereformed. It is believed that Example 20, which included HEAA as thehydroxyalkyl (meth)acrylate, did not provide wettable lenses because theHEAA contains two polar groups, the amide and hydroxyl groups, makingthe HEAA more polar than the other hydroxylalkyl (meth)acrylates used inExamples 18-19 and 21-22. It is believed that the increased polarity ofHEAA caused compatibility issues with the mPDMS. However, HEAA has thepotential to work with more polar silicones, such as SiMAA, OH-mPDMS,N-(2,3-dihydroxypropane)-N′-(propyl tetra(dimethylsiloxy)dimethylbutylsilane)acrylamide. Thus, a variety of hydroxylalkyl(meth)acrylate compounds can be used to form the hydrogels of thepresent invention.

TABLE 5 Example 17 18 19 20 21 22 Component HPMA HBMA DMHEMA HEAA GMMAGMMA NVP (wt %) 47.5 45.18 45.18 48.75 45.01 51.63 HOMA Cpd (wt %) 10.7513.07 13.07 9.50 13.23 6.62 HOMA:NVP (molar) 0.174 0.203 0.203 0.1880.408 0.204 % H₂O 58.9 (0.1) 54.5 60.4 NT* NT 62.6 % Haze 16 (0) 8 15NT* NT* 12 DCA 63 (5) 46 70 NT* NT* 49 MOD (psi) 73.4 (1.4) 120.5 68.7NT* NT* 70.4 Elong (%) 230.1 (1.8) 179.3 206.5 NT* NT* 203.5 Dk 93.493.4 90 NT* NT* 85.3 AC:RM 84 92 92 92 92 51 NT* = Not Tested

Examples 23-24 & Comparative Examples 3-6

Each reaction mixture was formed by mixing the components listed inTable 6 and degassed by applying vacuum at ambient temperature for about17(±3) minutes. The reaction mixture (75 μL) was then dosed at roomtemperature and <0.1% O₂, into thermoplastic contact lens molds(FC—Zeonor, BC Polypropylene) which had been degassed in N₂ box at RT(Compartment 1, FIG. 1) for a minimum of 12 hours prior to dosing. TheBC was placed on the FC mold and the lenses were moved into Compartment2 and cured for 20 minutes, an intensity of 4-5 mW/cm², <0.1% O₂, and62-65° C.

The molds were mechanically separated demolded (lenses remained in FC).The lenses were dry released by pressing on the back of the front curve.Lenses were extracted in DI water and equilibrated in borate bufferedpacking solution in lens vials and sterilized at 122° C. for 30 minutes.

The properties of the lenses were measured and are shown in Table 7,below.

TABLE 6 Component Ex. 23 24 CE3 CE4 CE5 CE6 mPDMS 16.50 16.50 16.5016.50 16.50 16.50 1000 OH-mPDMS, 27.50 27.50 27.50 27.50 27.50 27.50 n =4 NVP 46.65 44.15 41.65 39.15 35.15 23.35 HEMA 6.75 6.75 6.75 6.75 6.756.75 DMA 0.00 2.50 5.00 7.50 11.50 23.30 EGDMA 0.35 0.35 0.35 0.35 0.350.35 Norbloc 1.75 1.75 1.75 1.75 1.75 1.75 CGI 819 0.50 0.50 0.50 0.500.50 0.50 Diluent 10.00 10.00 10.00 10.00 10.00 10.00 TAA 100.00 100.00100.00 100.00 100.00 100.00

TABLE 7 Mechanicals Mod. Elong. Ex # % H₂O % Haze DCA (psi) (%) Dk AC:RMEx 23 61 (0) 6 (1) 48 (6) 75 (10) 145 (57) 92 59 Ex 24 63 (0) 7 (1) 79(9) 57 (6) 171 (36) 89 84 CE3 63 (0) 9 (1) 107 (3) 52 (4) 164 (53) 89110 CE4 63 (0) 9 (1) 110 (4) 46 (6) 162 (45) 89 135 CE5 60 (0) 6 (1) 119(15) 53 (6) 184 (56) 85 175 CE6 56 (0) 4 (0) 114 (13) 66 (6) 195 (44) 72294

DMA is a hydrophilic component with intermediate reaction kinetics. Itcan be seen from the data in Table 7, that amounts of DMA as small as2.5 wt % (Example 24), dramatically decrease the modulus, but increasethe contact angle of the resulting contact lenses.

Example 25 and Comparative Examples 5-8

Each reaction mixture was formed by mixing the components listed inTable 8 and degassed by applying vacuum at ambient temperature for about17(±3) minutes. The reaction mixture (75 μL) was then dosed at roomtemperature and <0.1% O₂, into thermoplastic contact lens molds(FC—Zeonor, BC Polypropylene) which had been degassed in N₂ box at RT(Compartment 1, FIG. 1) for a minimum of 12 hours prior to dosing. TheBC was placed on the FC mold and the lenses were moved into Compartment2 and cured for 20 minutes, an intensity of 4-5 mW/cm², <0.1% O₂, and62-65° C.

The molds were mechanically separated demolded (lenses remained in FC).The lenses were dry released by pressing on the back of the front curve.Lenses were extracted in DI water and equilibrated in borate bufferedpacking solution in lens vials and sterilized at 122° C. for 30 minutes.

TABLE 8 Component Ex. 25 CE5 CE6 CE7 SA2 50.00 50.00 50.00 50.00 VMA40.65 30.50 20.35 10.15 HEMA 6.75 6.75 6.75 6.75 DMA 0.00 10.15 20.3030.50 EGDMA 0.35 0.35 0.35 0.35 Norbloc 1.75 1.75 1.75 1.75 CGI 819 0.500.50 0.50 0.50 Diluent 10.00 10.00 10.00 10.00 TAA 100.00 100.00 100.00100.00

TABLE 9 Mechanicals % % Mod. Elong. Ex # Lens H₂O Haze DCA (psi) (%) DkAC:RM 25 2766- 58 (1) 36 (2) 62 (9) 299 (32) 320 (62) 93 59 140A CE52766- 65 (1) 10 (1) 117 (14) 42 (6) 337 (75) 75 162 140B CE6 2766- 58(0) 10 (1) 120 (7) 44 (4) 375 (66) 55 264 140C CE7 2766- 48 (0) 19 (2)123 (12) 95 (9) 399 (95) 37 367 140D

Addition of 10.15 wt % of DMA in the formulation of Comparative Examples5 dramatically reduced the Dk from 93 to 75, and increased the contactangle from 62 to 177. However, the addition of DMA also lowered themodulus of the resulting lenses dramatically. Amounts of DMA less thanabout 5 wt % would have a lower AC:RM ratio, and would produce lenseshaving a better overall balance of properties.

Examples 26 and 27

Reaction mixtures were formed from the components listed in Table 10.Lenses were made using the procedure described in Example 25. Theproperties of the lenses were measured and are reported in Table 11.

The contact lenses were clinically evaluated in a non-randomized,unmasked, bilateral, single day dispensing study with a lens wear timeof 12 (+/−2) hours. The lenses were worn by 10 subjects. Front surfacedeposition was observed after 60 minutes of contact lens wear and at thefollow-up post dispensing visit. Deposits were rated using the followingscale:

Grade 0 None No deposition. Grade 1 Slight Deposition, which occupies1-5% of the lens surface area. Grade 2 Mild Deposition, which occupies6-15% of the lens surface area. Grade 3 Moderate Deposition, whichoccupies 16-25% of the lens surface area. Grade 4 Severe Deposition,which occupies 26% of the lens surface area.Strehl ratios (4^(th) order) were measured on a Mach-Zehnderinterferometer, using a 5 mm aperture across the optic zone. The valuesare shown in Table 11, below.

TABLE 10 Component Ex. 26 Ex. 27 mPDMS 1000 16.50 17.45 OH-mPDMS, n = 427.50 29.90 NVP 46.65 43.98 HEMA 6.73 6.00 Blue HEMA 0.02 0.02 EGDMA0.45 0.00 TEGDMA 0.00 0.20 TAC 0.00 0.20 Norbloc 1.75 1.75 CGI 819 0.500.50 Diluent 0.00 5.00 TAA 100.00 100.00

TABLE 11 EX. # 26 27 % H₂O 53 (0) 54 (0) % Haze NT NT DCA 34 (9) 50 (9)Mod. (psi) 154 (10) 106 (8) Elong. (%) 171 (24) 296 (34) Dk 96 NT SR0.9718 (0.0176) 0.9836 (0.0044) SR = Strehl Ratio (4^(th) order)

TABLE 12 Front Post Fit - 60 Mins Follow Up Surface n (%) n (%)Deposition Ex. 26 Ex. 27 Ex 26 Ex. 27 Grade 0 17 (85%) 13 (93%) 5 (25%)1 (7%) Grade 1  3 (15%) 1 (7%) 7 (35%) 13 (93%) Grade 2 0 0 8 (40%) 0Grade 3 0 0 0 0 Grade 4 0 0 0 0 Total Eyes 20  14  20  14 

Synthetic Example 1 Preparation of VINAL

4.82 g vinyl chloroformate was added to a mixture of 8.19 g β-alanine(Aldrich) in 74 ml acetonitrile. The resulting mixture was refluxed for2 hours, then cooled to room temperature and allowed to sit for 2 hours.It was filtered and solvent was removed under reduced pressure. Thecrude product was dissolved in 30 ml distilled water and washed threetimes with ethyl acetate. The combined ethyl acetate washes were washedwith 50 ml deionized water. Solvent was evaporated from the combinedethyl acetate washes to yield 4.5 g product as a fluffy yellowish solid.¹H NMR: 7.1 ppm (dd, 1H), 5.4 ppm (br s, OH), 4.7 ppm (dd, 1H), 4.4 ppm(dd, 1H), 3.5 ppm (q, 2H), 2.6 ppm (t, 2H).

Synthetic Example 2 Preparation of 2-Hydroxybutyl Methacrylate (HBMA)

A blend of 72 grams 1,2-epoxybutane (Aldrich), 0.85 g 4-methoxyphenol(Aldrich), and 6.5 g potassium hydroxide was stirred in a 500 ml roundbottomed flask equipped with an addition funnel and thermocouplethermometer. 172 g methacrylic acid was added via the addition funnel,and the blend was slowly to 75° C., and stirred overnight under an air,then increased to 88° C. for 4 hours. The mixture was cooled, and 700 mlof 2.0 N NaOH was added to the mixture in a separatory funnel. The upperlayer was washed with borate buffered saline three times. Ethyl ether(200 ml) was added to the combined saline washes to extract any product.The combined organic layers were dried over NaSO₄. The NaSO₄ wasfiltered out and the product was distilled (90-98° C./˜4 mm Hg). 17.5 gproduct was collected, to which was added 4 mg 4-methoxyphenol. ¹H NMR:6.1 ppm (1H, m), 5.5 (1H, m), 4.8 (0.25H m), 4.2 (0.64 H, dd, 8.1 and11.7 Hz), 4.0 (0.64 Hz, dd, 6.9 and 11.4 Hz), 3.6-3.8 1.26H, m), 2.3(OH, br s), 1.9 (3H, m), 1.4-1.7 (2H, m), 0.9 (3H, m); consistent with ablend of 2-hydroxy-1-propylmethacrylate and1-hydroxy-2-propylmethacrylate.

Synthetic Example 3 Preparation of Dimethylhydroxyethylmethacrylate

The same procedure as for HBMA was used, but substituting1,2-epoxy-2-methylpropane for the 1,2-epoxypropane. The product wasisolated by distillation at 47-48°/0.4-0.6 mm Hg. ¹H NMR: 6.1 ppm (1H,s), 5.5 (1H, m), 4.0 (2H, s), 2.1 (OH, br s), 1.9 (3H, s), 1.2 (6H, m);consistent 2-hydroxy-2-methyl propylmethacrylate(dimethylhydroxyethylmethacrylate).

1. A silicone hydrogel comprising a water content of at least about 50%and an oxygen permeability of at least about 80 barrers wherein saidsilicone hydrogel is formed from a reaction mixture comprising about 37to about 75 wt % of at least one hydrophilic monomer selected from thegroup consisting of N-vinylamide monomer of Formula I, vinyl pyrrolidoneof Formula II-IV, N-vinyl piperidone of Formula V:

wherein R is H or methyl; R₁, R₂, R₃, R₆, R₇, R₁₀, and R₁₁ areindependently selected from the group consisting of H, CH₃, CH₂CH₃,CH₂CH₂CH₃, C(CH₃)₂; R₄ and R₈ are independently selected from the groupconsisting of CH₂, CHCH₃ and C(CH₃); R₅ is selected from H, methyl,ethyl; and R₉ is selected from CH═CH₂, CCH₃═CH₂, and CH═CHCH₃; at leastone silicone-containing component; selected from the group consisting ofat least one mono (meth)acryloxyalkyl polydialkylsiloxane monomer ofFormula VII or styryl polydialkylsiloxane monomer of Formula VIII:

wherein R₁₂ is H or methyl; X is O or NR₁₆; Each R₁₄ is independently aC₁ to C₄ alkyl which may be fluorine substituted, or phenyl; R₁₅ is a C₁to C₄ alkyl; R₁₃ is a divalent alkyl group, which may further befunctionalized with a group selected from the group consisting of ethergroups, hydroxyl groups, carbamate groups and combinations thereof; a is3 to 50; R₁₆ is selected from H, C1-4, which may be further substitutedwith one or more hydroxyl groups; at least one hydroxyl-containingcomponent selected from said silicone-containing components substitutedwith at least one hydroxyl group, at least one hydroxyalkyl monomer, andmixtures thereof, wherein, said reaction mixture comprising between 9and 14% silicon and less than 15 wt % TRIS and wherein all reactivecomponents other than said hydrophilic monomer and said siliconecontaining components in the reaction mixture are present in an amountbetween about 11 and about 92 mmol/g reactive components.
 2. Thesilicone hydrogel of claim 1 wherein said silicone containing componentscomprise less than 10 wt % TRIS.
 3. The silicone hydrogel of claim 1wherein said silicone containing components are free of TRIS.
 4. Thesilicone hydrogel of claim 1 wherein all ancillary components arepresent in said reaction mixture in a concentration of less than 12 wt %based upon reactive components.
 5. The silicone hydrogel of claim 1wherein said water content is at least about 55%.
 6. The siliconehydrogel of claim 1 wherein said water content is at least about 60%. 7.The silicone hydrogel of claim 1, 5 or 6 wherein said oxygenpermeability is at least about 90 barrers.
 8. The silicone hydrogel ofclaim 1, 5 or 6 wherein said oxygen permeability is at least about 100barrers.
 9. The silicone hydrogel of claim 1 wherein said ancillarycomponents comprise between about 38 and about 76 mmol/g reactivecomponents.
 10. The silicone hydrogel of claim 1, 5 or 6 wherein saidoxygen permeability is between about 85 and about 150 barrers.
 11. Thesilicone hydrogel of claim 1, 5 or 6 wherein said oxygen permeability isbetween about 85 and about 130 barrers.
 12. The silicone hydrogel ofclaim 1, 5 or 6 further comprising a modulus of less than about 150 psi.13. The silicone hydrogel of claim 1, 5 or 6 further comprising acontact angle of less than about 80°.
 14. The silicone hydrogel of claim1, 5 or 6 further comprising an advancing contact angle of less thanabout 70°.
 15. The silicone hydrogel of claim 1 wherein saidhydroxyalkyl monomer is selected from the group consisting of at leastone hydroxyalkyl (meth)acrylate or (meth)acrylamide monomer of FormulaIX or a styryl compound of Formula X

wherein R₁ is H or methyl, X is O or NR₁₆, R₁₆ is a H, C₁ to C₄ alkyl,which may be further substituted with at least one OH; R₁₇ is selectedfrom C₂-C₄ mono or dihydroxy substituted alkyl, and poly(ethyleneglycol) having 1-10 repeating units; wherein said at least onehydroxyalkyl (meth)acrylate or (meth)acrylamide monomer and said slowreacting monomer are present in mole percents which form a molar ratiobetween about 0.15 and 0.4.
 16. The silicone hydrogel of claim 1 whereinsaid at least one hydrophilic monomer is selected from the groupconsisting of N-vinylamide monomer of Formula I, vinyl pyrrolidone ofFormula II or IV:

wherein R is H or methyl; R₁, R₂, R₃, R₁₀, and R₁₁ are independentlyselected from the group consisting of H, CH₃, CH₂CH₃, CH₂CH₂CH₃,C(CH₃)₂; R₄ is selected from the group consisting of CH₂, CHCH₃ andC(CH₃); R₅ is selected from H, methyl, ethyl; and R₉ is selected fromCH═CH₂, CCH₃═CH₂, and CH═CHCH₃; (b) said at least onesilicone-containing component is selected from the group consisting ofat least one mono (meth)acryloxyalkyl polydialkylsiloxane monomer ofFormula VII:

wherein R₁₂ is H or methyl; X is O or NR₁₆; Each R₁₄ is independently aC₁ to C₄ alkyl which may be fluorine substituted, or phenyl; R₁₅ is a C₁to C₄ alkyl; R₁₃ is a divalent alkyl group, which may further befunctionalized with a group selected from the group consisting of ethergroups, hydroxyl groups, carbamate groups and combinations thereof; a is3 to 50; R₁₆ is selected from H, C₁₋₄, which may be further substitutedwith one or more hydroxyl groups; (c) at least one hydroxylalkyl monomeris selected from the group consisting of hydroxyalkyl (meth)acrylate or(meth)acrylamide monomer of Formula IX

wherein R₁ is H or methyl, X is O or NR₁₆, R₁₆ is a H, C₁ to C₄ alkyl,which may be further substituted with at least one OH; R₁₇ is selectedfrom C₂-C₄ mono or dihydroxy substituted alkyl, and poly(ethyleneglycol) having 1-10 repeating units; wherein said at least onehydroxyalkyl (meth)acrylate or (meth)acrylamide monomer and said slowreacting monomer are present in mole percents which form a molar ratiobetween about 0.15 and 0.4.
 17. The silicone hydrogel of claim 15 or 16wherein each R₃ is independently selected from ethyl and methyl groups.18. The silicone hydrogel of claim 15 or 16 wherein all R₃ are methyl.19. The silicone hydrogel of claim 15 or 16 wherein R₁₃ is selected fromthe group consisting of C₁-C₆ alkylene group which may be substitutedwith ether, hydroxyl and combinations thereof.
 20. The silicone hydrogelof claim 15 or 16 wherein R₁₃ is selected from the group consisting ofC₁ or C₃-C₆ alkylene groups which may be substituted with ether,hydroxyl and combinations thereof.
 21. The silicone hydrogel of claim 15or 16 wherein R₁₆ is H or methyl.
 22. The silicone hydrogel of claim 15or 16 wherein R₁₂ and each R₁₄ are methyl.
 23. The silicone hydrogel ofclaim 15 or 16 wherein at least one R₁₄ is 3,3,3-trifluoropropyl. 24.The silicone hydrogel of claim 15 or 16 wherein R₄ is methyl or2-hydroxyethyl.
 25. The silicone hydrogel of claim 15 wherein a is 5 to15.
 26. The silicone hydrogel of claim 15 or 16 wherein theslow-reacting hydrophilic monomer is selected from the vinyl pyrrolidoneof Formula II or IV or the N-vinyl amide monomer of Formula I, having atotal number of carbon atoms in R₁ and R₂ of 4 or less.
 27. The siliconehydrogel of claim 15 or 16 wherein the hydrophilic monomer is selectedfrom a vinyl pyrrolidone of Formula III or IV and R₆ is methyl, R₇ ishydrogen, R₉ is CH═CH₂, R₁₀ and R₁₁ are H.
 28. The silicone hydrogel ofclaim 15 or 16 wherein the hydrophilic monomer is selected from ethyleneglycol vinyl ether (EGVE), di(ethylene glycol) vinyl ether (DEGVE),N-vinyl pyrrolidone (NVP), 1-methyl-3-methylene-2-pyrrolidone,1-methyl-5-methylene-2-pyrrolidone, 5-methyl-3-methylene-2-pyrrolidone;1-ethyl-5-methylene-2-pyrrolidone, N-methyl-3-methylene-2-pyrrolidone,5-ethyl-3-methylene-2-pyrrolidone, 1-n-propyl-3-methylene-2-pyrrolidone,1-n-propyl-5-methylene-2-pyrrolidone,1-isopropyl-3-methylene-2-pyrrolidone,1-isopropyl-5-methylene-2-pyrrolidone, N-vinyl-N-methyl acetamide (VMA),N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,N-vinyl acetamide, N-vinyl isopropylamide, allyl alcohol, N-vinylcaprolactam, N-2-hydroxyethyl vinyl carbamate, N-carboxy-β-alanineN-vinyl ester; N-carboxyvinyl-β-alanine (VINAL),N-carboxyvinyl-α-alanine and mixtures thereof.
 29. The silicone hydrogelof claim 15 or 16 wherein the hydrophilic monomer is selected from thegroup consisting of N-vinylpyrrolidone, N-vinylacetamide,1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,5-methyl-3-methylene-2-pyrrolidone, and mixtures thereof.
 30. Thesilicone hydrogel of claim 15 or 16 wherein the hydrophilic monomer isselected from the group consisting of NVP, VMA and1-methyl-5-methylene-2-pyrrolidone.
 31. The silicone hydrogel of claim15 or 16 wherein the reacting hydrophilic monomer comprises NVP.
 32. Thesilicone hydrogel of claim 15 or 16 wherein R₁ is H or methyl, X isoxygen and R is selected from C₂-C₄ mono or dihydroxy substituted alkyl,and poly(ethylene glycol) having 1-10 repeating units.
 33. The siliconehydrogel of claim 15 or 16 wherein R₁ methyl, X is oxygen and R isselected from C₂-C₄ mono or dihydroxy substituted alkyl, andpoly(ethylene glycol) having 2-20 repeating units.
 34. The siliconehydrogel of claim 15 or 16 wherein at least one R₁₄ is3,3,3-trifluoropropyl.
 35. The silicone hydrogel of claim 15 or 16wherein R₁₃ is selected from C₁-C₆ alkylene groups which may besubstituted with ether, hydroxyl and combinations thereof.
 36. Thesilicone hydrogel of claim 15 or 16 wherein R₁₃ is selected from C₁ orC₃₋₆ alkylene groups which may be substituted with ether, hydroxyl andcombinations thereof.
 37. The silicone hydrogel of claim 15 or 16wherein a is 7 to
 30. 38. The silicone hydrogel of claim 15 or 16wherein R₁₆ is H or methyl.
 39. The silicone hydrogel of claim 1 whereinsaid monomethacryloxyalkylpolydimethylsiloxane methacrylate is selectedfrom the group consisting of monomethacryloxypropyl terminatedmono-n-butyl terminated polydimethylsiloxane, monomethacryloxypropylterminated mono-n-methyl terminated polydimethylsiloxane,monomethacryloxypropyl terminated mono-n-butyl terminatedpolydiethylsiloxane, monomethacryloxypropyl terminated mono-n-methylterminated polydiethylsiloxane, N-(2,3-dihydroxypropane)-N′-(propyltetra(dimethylsiloxy) dimethylbutylsilane)acrylamide;α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-octamethylpentasiloxaneand mixtures thereof.
 40. The silicone hydrogel of claim 1 wherein saidmonomethacryloxyalkylpolydimethylsiloxane methacrylate is selected fromthe group consisting of monomethacryloxypropyl terminated mono-n-butylterminated polydimethylsiloxane, monomethacryloxypropyl terminatedmono-n-methyl terminated polydimethylsiloxane,N-(2,3-dihydroxypropane)-N′-(propyl tetra(dimethylsiloxy)dimethylbutylsilane)acrylamide.
 41. The silicone hydrogel of claim 15 or16 wherein R₁ is H or methyl, X is oxygen and R is selected from C₂-C₄mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having1-10 repeating units.
 42. The silicone hydrogel of claim 15 or 16wherein R₁ methyl, X is oxygen and R is selected from C₂-C₄ mono ordihydroxy substituted alkyl, and poly(ethylene glycol) having 2-20repeating units.
 43. The silicone hydrogel of claim 15 or 16 wherein Ris 2-hydroxyethyl, 2,3-dihydroxypropyl, 2-hydroxypropyl.
 44. Thesilicone hydrogel of claim 1 wherein said hydroxyalkyl monomer isselected from the group consisting of 2-hydroxyethyl (meth)acrylate,3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,1-hydroxypropyl-2-(meth)acrylate, 2-hydroxy-2-methyl-propyl(meth)acrylate, 3-hydroxy-2,2-dimethyl-propyl (meth)acrylate,4-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate, 2-hydroxyethyl(meth)acrylamide, polyethyleneglycol monomethacrylate,bis-(2-hydroxyethyl) (meth)acrylamide, 2,3-dihydroxypropyl(meth)acrylamide, and mixtures thereof.
 45. The silicone hydrogel ofclaim 1 wherein said hydroxyalkyl monomer is selected from the groupconsisting of 2-hydroxyethyl methacrylate, glycerol methacrylate,2-hydroxypropyl methacrylate, hydroxybutyl methacrylate,3-hydroxy-2,2-dimethyl-propyl methacrylate, and mixtures thereof. 46.The silicone hydrogel of claim 1 wherein said hydroxyalkyl monomercomprises 2-hydroxyethyl methacrylate, 3-hydroxy-2,2-dimethyl-propylmethacrylate, glycerol methacrylate and mixtures comprising them. 47.The silicone hydrogel of claim 1 further comprising a contact angle ofless than about 80°.
 48. The silicone hydrogel of claim 1 furthercomprising a % haze of less than about 50%.
 49. The silicone hydrogel ofclaim 1 further comprising a % haze of less than about 10%.
 50. Thesilicone hydrogel of claim 1 wherein said reaction mixture furthercomprises at least one slow reacting crosslinker and at least one fastreacting crosslinker.
 51. The silicone hydrogel of claim 50 wherein saidat least one slow reacting crosslinker and at least one fast reactingcrosslinker are each present in said reaction mixture in amounts betweenabout 0.05 to about 0.3 wt %.
 52. The silicone hydrogel of claim 50wherein said at least one slow reacting crosslinker and at least onefast reacting crosslinker are each present in said reaction mixture inamounts between about 0.1 to about 0.2 wt %.
 53. The silicone hydrogelof claim 1 wherein said at least one silicone-containing component andsaid at least one hydroxyl-containing component have the same reactivefunctionality.